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Index of Diseases

Instructions. To find the proper medical term, scroll up and down to review the alphabetical listings. Also, you can use the "Page Up" and "Page down" key on your keyboard. Or use the search function of your browser. In both Netscape and Explorer, go to "Edit" and select "Find in Page". Type in the main term of interest. Frequently, it is best to type in only the first 4 or five letters (i.e., "prost" for prostate) because that will find more alternative terms from which to select the proper one.

L

Labor Complications

Definition: Medical problems associated with LABOR, OBSTETRIC including cephalopelvic disproportion, hemorrhage, FETAL DISTRESS, or other disorders.
Annotation: check tags FEMALE & PREGNANCY; DF: LABOR COMPL
ID#: D007744

Labor, Premature

Definition: Onset of LABOR, OBSTETRIC before term but after the fetus has become viable, usually sometime during the 29th through 38th week of gestation.
Annotation: "tokolysis": translate as "tocolysis" & index as TOCOLYSIS; eff of drugs on premature labor: consider also TOCOLYTIC AGENTS; check tags FEMALE & PREGNANCY
ID#: D007752

Laboratory Infection

Definition: Accidentally acquired infection in laboratory workers.
Annotation: "accidentally acquired infect in laboratory"; IM; coord with specific infection (IM) + lab animal (IM)
ID#: D007757

Labyrinth Diseases

Definition:
Annotation: inflamm dis = LABYRINTHITIS
ID#: D007759

Labyrinthitis

Definition: Inflammation of the inner ear.
Annotation: inflamm of inner ear
ID#: D007762

Lacerations

Definition: Torn, ragged, mangled wounds.
Annotation:
ID#: D022125

Lacrimal Apparatus Diseases

Definition: Diseases of the lacrimal apparatus.
Annotation: inflamm dis = DACRYOCYSTITIS
ID#: D007766

Lacrimal Duct Obstruction

Definition: Interference with the secretion of tears by the lacrimal glands. Obstruction of the lacrimal sac or nasolacrimal duct causing acute or chronic inflammation of the lacrimal sac (DACRYOCYSTITIS). It is caused also in infants by failure of the nasolacrimal duct to open into the inferior meatus and occurs about the third week of life. In adults occlusion may occur spontaneously or after injury or nasal disease. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p250)
Annotation:
ID#: D007767

Lactation Disorders

Definition: Disturbances of milk secretion in either sex, not necessarily related to pregnancy.
Annotation: in both sexes & not necessarily related to pregn; usually check tag FEMALE
ID#: D007775

Lactose Intolerance

Definition: The condition resulting from the absence or deficiency of LACTASE in the MUCOSA cells of the GASTROINTESTINAL TRACT, and the inability to break down LACTOSE in milk for ABSORPTION. Bacterial fermentation of the unabsorbed lactose leads to symptoms that range from a mild indigestion (DYSPEPSIA) to severe DIARRHEA. Lactose intolerance may be an inborn error or acquired.
Annotation:
ID#: D007787

Lafora Disease

Definition: A form of stimulus sensitive myoclonic epilepsy inherited as an autosomal recessive condition. The most common presenting feature is a single seizure in the second decade of life. This is followed by progressive myoclonus, myoclonic seizures, tonic-clonic seizures, focal occipital seizures, intellectual decline, and severe motor and coordination impairments. Most affected individuals do not live past the age of 25 years. Concentric amyloid (Lafora) bodies are found in neurons, liver, skin, bone, and muscle (From Menkes, Textbook of Childhood Neurology, 5th ed, pp111-110)
Annotation:
ID#: D020192

Lambert-Eaton Myasthenic Syndrome

Definition: An autoimmune disease characterized by weakness and fatigability of proximal muscles, particularly of the pelvic girdle, lower extremities, trunk, and shoulder girdle. There is relative sparing of extraocular and bulbar muscles. CARCINOMA, SMALL CELL of the lung is a frequently associated condition, although other malignancies and autoimmune diseases may be associated. Muscular weakness results from impaired impulse transmission at the NEUROMUSCULAR JUNCTION. Presynaptic calcium channel dysfunction leads to a reduced amount of acetylcholine being released in response to stimulation of the nerve. (From Adams et al., Principles of Neurology, 6th ed, pp 1471)
Annotation:
ID#: D015624

Lameness, Animal

Definition: A departure from the normal gait in animals.
Annotation: coord IM with precoord animal/dis term (IM) + animal (NIM); don't forget also check tag ANIMALS
ID#: D007794

Landau-Kleffner Syndrome

Definition: A syndrome characterized by the onset of isolated language dysfunction in otherwise normal children (age of onset 4-7 years) and epileptiform discharges on ELECTROENCEPHALOGRAPHY. Seizures, including atypical absence (EPILEPSY, ABSENCE), complex partial (EPILEPSY, COMPLEX PARTIAL), and other types may occur. The electroencephalographic abnormalities and seizures tend to resolve by puberty. The language disorder may also resolve although some individuals are left with severe language dysfunction, including APHASIA and auditory AGNOSIA. (From Menkes, Textbook of Child Neurology, 5th ed, pp749-50; J Child Neurol 1997 Nov;12(8):489-495)
Annotation:
ID#: D018887

Langer-Giedion Syndrome

Definition: Autosomal dominant disorder characterized by cone-shaped epiphyses in the hands and multiple cartilaginous exostoses. Mental retardation and abnormalities of chromosome 8 are often present. The exostoses in this syndrome appear identical to those of hereditary multiple exostoses (EXOSTOSES, HEREDITARY MULTIPLE).
Annotation: an osteochondrodysplasia
ID#: D015826

Language Development Disorders

Definition: Conditions characterized by language abilities (comprehension and expression of speech and writing) that are below the expected level for a given age, generally in the absence of an intellectual impairment. These conditions may be associated with DEAFNESS; BRAIN DISEASES; MENTAL DISORDERS; or environmental factors.
Annotation: do not confuse with LANGUAGE DISORDERS, disord of use or comprehension of language: LANGUAGE DEVELOPMENT DISORDERS is "failure to understand or speak the language at the expected age"; DF: LANGUAGE DEVELOPMENT DIS
ID#: D007805

Language Disorders

Definition: Conditions characterized by deficiencies of comprehension or expression of written and spoken forms of language. These include acquired and developmental disorders.
Annotation: /ther: consider also LANGUAGE THERAPY; do not confuse with SPEECH DISORDERS: read differentiation of LANGUAGE & SPEECH under LANGUAGE; do not confuse with LANGUAGE DEVELOPMENT DISORDERS: see note there
ID#: D007806

Larva Migrans

Definition: Infections caused by nematode larvae which never develop into the adult stage and migrate through various body tissues. They commonly infect the skin, eyes, and viscera in man. Ancylostoma brasiliensis causes cutaneous larva migrans. Toxocara causes visceral larva migrans.
Annotation: note category: a disease; restrict this dis to nematode infections; Ancylostoma brasiliensis causes cutaneous larva migrans, Toxocara causes visceral
ID#: D007815

Larva Migrans, Visceral

Definition: A condition produced in man by the prolonged migration of animal nematode larvae in extraintestinal tissues other than skin; characterized by persistent hypereosinophilia, hepatomegaly, and frequently pneumonitis, commonly caused by Toxocara canis and Toxocara cati.
Annotation: note category: a disease; in human only, caused by Toxocara: coord IM with TOXOCARA CANIS (IM) if caused by T. canis but not with TOXOCARA if by T. cati; in animal probably = TOXOCARIASIS
ID#: D007816

Laryngeal Diseases

Definition: Disorders of the larynx, general or unspecified.
Annotation: inflamm dis = LARYNGITIS; laryngocele: index under LARYNX /abnorm
ID#: D007818

Laryngeal Edema

Definition: Edema of any region of the larynx from a variety of causes. In the earliest stages it may be difficult to differentiate from infection, although mucosal injection and erythema are found more often in the latter. Allergic edema may result as a response from provocation induced by foods, inhalants, and drugs. The entire respiratory tract or only an isolated portion of the larynx may be affected. Laryngeal edema may also be hereditary. Other possible causes of laryngeal edema include increased capillary pressure due to superior vena cava syndrome, internal jugular vein ligation, lowered plasma osmotic failure induced by renal failure, impaired lymphatic flow, and increased capillary permeability to proteins. (From Paparella et al., Otolaryngology, 3d ed, p2253)
Annotation:
ID#: D007819

Laryngeal Neoplasms

Definition: Cancers or tumors of the LARYNX or any of its parts: the GLOTTIS, EPIGLOTTIS, LARYNGEAL CARTILAGES, LARYNGEAL MUSCLES, and VOCAL CORDS.
Annotation: coord IM with histol type of neopl (IM); laryngeal polyps = LARYNGEAL NEOPLASMS (IM) + POLYPS (IM)
ID#: D007822

Laryngismus

Definition: Spasm of the larynx.
Annotation: "spasm of the larynx": note X ref
ID#: D007826

Laryngitis

Definition: Inflammation of the larynx. This condition presents itself with dryness and soreness of the throat, difficulty in swallowing, cough, and hoarseness.
Annotation:
ID#: D007827

Laryngostenosis

Definition: Stricture or narrowing of the larynx. This condition may be developmental or acquired; with progressive respiratory difficulty as a symptom.
Annotation: narrowing or stricture of larynx; do not confuse with spasmodic closure ( = LARYNGOSPASM or LARYNGISMUS)
ID#: D007829

Lassa Fever

Definition: An acute febrile human disease caused by the LASSA VIRUS.
Annotation: a hemorrhagic fever caused by an arenavirus
ID#: D007835

Lateral Medullary Syndrome

Definition: Infarction of the dorsolateral aspect of the medulla due to occlusion of the vertebral artery and/or the posterior inferior cerebellar artery. Clinical manifestations vary with the size of infarction, but may include loss of pain and temperature sensation in the ipsilateral face and contralateral body below the chin; ipsilateral HORNER SYNDROME; ipsilateral ATAXIA; DYSARTHRIA; VERTIGO; nausea, hiccup; dysphagia; and VOCAL CORD PARALYSIS. (From Adams et al., Principles of Neurology, 6th ed, p801)
Annotation:
ID#: D014854

Lateral Sinus Thrombosis

Definition: Infectious or noninfectious thrombosis of the lateral sinus of the brain. Septic thrombosis may be associated with OTITIS MEDIA or MASTOIDITIS. CRANIOCEREBRAL TRAUMA; BRAIN NEOPLASMS; NEUROSURGICAL PROCEDURES; THROMBOPHILIA; and other conditions may result in non-septic thrombosis. Clinical manifestations include headache, vertigo, and increased intracranial pressure. Extension of the thrombus into adjacent venous structures may result in INTRACRANIAL HEMORRHAGES or SEIZURES. (From Joynt, Clinical Neurology, 1997, Ch23, pp60-8)
Annotation:
ID#: D020227

Latex Hypersensitivity

Definition: Allergic reaction to products containing processed natural rubber latex such as rubber gloves, condoms, catheters, dental dams, balloons, and sporting equipment. Both T-cell mediated (HYPERSENSITIVITY, DELAYED) and IgE antibody-mediated (HYPERSENSITIVITY, IMMEDIATE) allergic responses are possible. Delayed hypersensitivity results from exposure to antioxidants present in the rubber; immediate hypersensitivity results from exposure to a latex protein.
Annotation: coord with HYPERSENSITIVITY, IMMEDIATE or HYPERSENSITIVITY, DELAYED if pertinent
ID#: D020315

Lathyrism

Definition: A paralytic condition of the legs caused by ingestion of lathyrogens, especially beta-aminopropionitrile, found in the seeds of plants of the genus Lathyrus (see FABACEAE).
Annotation: if nitrile-induced, index also under the nitrile, probably NIM
ID#: D007842

Laurence-Moon Syndrome

Definition: An autosomal recessive condition characterized by hypogonadism; spinocerebellar degeneration; MENTAL RETARDATION; RETINITIS PIGMENTOSA; and OBESITY. This syndrome was previously referred to as Laurence-Moon-Biedl syndrome until BARDET-BIEDL SYNDROME was identified as a distinct entity. (From N Engl J Med. 1989 Oct 12;321(15):1002-9)
Annotation: note X ref: do not confuse with LAURENCE-MOON-BARDET-BIEDL SYNDROME see BARDET-BIEDL SYNDROME
ID#: D007849

Lead Poisoning

Definition:
Annotation: occup lead pois: coord IM with OCCUPATIONAL DISEASES (IM) but not also ENVIRONMENTAL EXPOSURE (see note there); in infant or child = LEAD POISONING, NERVOUS SYSTEM, CHILDHOOD; in adolescent or adult, consider also LEAD POISONING, NERVOUS SYSTEM, ADULT
ID#: D007855

Lead Poisoning, Nervous System

Definition: Injury to the nervous system secondary to exposure to lead compounds. Two distinct clinical patterns occur in children (LEAD POISONING, CHILDHOOD) and adults (LEAD POISONING, ADULT). In children, lead poisoning typically produces an encephalopathy. In adults, exposure to toxic levels of lead is associated with a peripheral neuropathy.
Annotation: prefer specifics: in infant or child = LEAD POISONING, NERVOUS SYSTEM, CHILDHOOD; in adolescent or adult = LEAD POISONING, NERVOUS SYSTEM, ADULT
ID#: D020263

Lead Poisoning, Nervous System, Adult

Definition: Neurologic conditions in adults associated with acute or chronic exposure to lead or any of its salts. The most common lead related neurologic syndrome in adults consists of a polyneuropathy involving motor fibers. This tends to affect distal nerves and may present as wrist drop due to RADIAL NEUROPATHY. Additional features of chronic lead exposure include ANEMIA; CONSTIPATION; colicky abdominal pain; a bluish lead line of the gums; interstitial nephritis (NEPHRITIS, INTERSTITIAL); and saturnine gout. An encephalopathy may rarely occur. (From Adams et al., Principles of Neurology, 6th ed, p1212)
Annotation: includes adolescent as well as adult; coord with specific nervous system symptoms if emphasized
ID#: D020265

Lead Poisoning, Nervous System, Childhood

Definition: Neurologic disorders occurring in children following lead exposure. The most frequent manifestation of childhood lead toxicity is an encephalopathy associated with chronic ingestion of lead that usually presents between the ages of 1 and 3 years. Clinical manifestations include behavioral changes followed by lethargy; CONVULSIONS; HALLUCINATIONS; DELIRIUM; ATAXIA; and vomiting. Elevated intracranial pressure (HYPERTENSION, INTRACRANIAL) and CEREBRAL EDEMA may occur. (From Adams et al., Principles of Neurology, 6th ed, p1210-2)
Annotation: includes infant as well as child; coord with specific nervous system symptoms if emphasized
ID#: D020264

Learning Disorders

Definition: Conditions characterized by a significant discrepancy between an individual's perceived level of intellect and their ability to acquire new language and other cognitive skills. These disorders may result from organic or psychological conditions. Relatively common subtypes include DYSLEXIA, dyscalculia, and dysgraphia.
Annotation:
ID#: D007859

Lecithin Acyltransferase Deficiency

Definition: A disease characterized by deficiency or low levels of plasma lecithin cholesterol acyl transferase. Clinical manifestations include corneal opacity, anemia, and proteinuria.
Annotation: a hypolipoproteinemia; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D007863

Leg Dermatoses

Definition: A nonspecific term used to denote any cutaneous lesion or group of lesions, or eruptions of any type on the leg. (From Stedman, 25th ed)
Annotation: GEN & as coord for specific skin diseases of the leg but not as coord for neoplasms on the leg (use neopl coords (IM) with LEG (IM)); consider synonym for leg dermatitis & do not add DERMATITIS unless one of the specific DERMATITIS terms in MeSH
ID#: D007868

Leg Injuries

Definition: General or unspecified injuries involving the leg.
Annotation: GEN or unspecified; consider also /inj with specific parts of the leg; /vet permitted for non-primates
ID#: D007869

Leg Length Inequality

Definition: A condition in which one of a pair of legs fails to grow as long as the other, which could result from injury or surgery.
Annotation: correction of inequality: coord IM with BONE LENGTHENING (IM) or specifically ILIZAROV TECHNIQUE (IM) if pertinent
ID#: D007870

Leg Ulcer

Definition: Ulceration of the skin and underlying structures of the lower extremity. About 90% of the cases are due to venous insufficiency (VARICOSE ULCER), 5% to arterial disease, and the remaining 5% to other causes.
Annotation: if varicose, index instead under VARICOSE ULCER; FOOT ULCER is also available
ID#: D007871

Legg-Perthes Disease

Definition: A particular type of FEMUR HEAD NECROSIS occurring in children, mainly male, with a course of four years or so.
Annotation: a type of femur head necrosis
ID#: D007873

Legionellosis

Definition: Infections with bacteria of the genus LEGIONELLA.
Annotation: gram-neg bact infect by any species of Legionella except L. pneumophila ( = LEGIONNAIRES' DISEASE)
ID#: D007876

Legionnaires' Disease

Definition: An acute, sometimes fatal, pneumonia-like bacterial infection characterized by high fever, malaise, muscle aches, respiratory disorders and headache. It is named for an outbreak at the 1976 Philadelphia convention of the American Legion.
Annotation: caused by Legionella pneumophila: infect by other Legionella species = LEGIONELLOSIS
ID#: D007877

Leigh Disease

Definition: A group of metabolic disorders primarily of infancy characterized by the subacute onset of psychomotor retardation, hypotonia, ataxia, weakness, vision loss, eye movement abnormalities, seizures, dysphagia, and lactic acidosis. Pathological features include spongy degeneration of the neuropile of the basal ganglia, thalamus, brain stem, and spinal cord. Patterns of inheritance include X-linked recessive, autosomal recessive, and mitochondrial. Leigh disease has been associated with mutations in genes for the PYRUVATE DEHYDROGENASE COMPLEX; CYTOCHROME-C OXIDASE; ATP synthase subunit 6; and subunits of mitochondrial complex I. (From Menkes, Textbook of Child Neurology, 5th ed, p850).
Annotation:
ID#: D007888

Leiomyoma

Definition: A benign tumor derived from smooth muscle tissue, also known as a fibroid tumor. They rarely occur outside of the uterus and the gastrointestinal tract but can occur in the skin and subcutaneous tissues, probably arising from the smooth muscle of small blood vessels in these tissues.
Annotation: solitary; multiple = LEIOMYOMATOSIS; coord IM with precoord organ/neopl term (IM); for X refs FIBROID UTERUS; FIBROIDS, UTERINE & FIBROMA, UTERINE: coord with UTERINE NEOPLASMS (IM)
ID#: D007889

Leiomyoma, Epithelioid

Definition: A relatively rare smooth muscle tumor found most frequently in the wall of the gastrointestinal tract, especially in the stomach. It is similar to other smooth muscle tumors but may become very large and hemorrhage and exhibit small cystic areas. Simple excision is almost always curative. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1354)
Annotation: /blood supply /chem /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D018230

Leiomyomatosis

Definition: The state of having multiple leiomyomas throughout the body. (Stedman, 25th ed)
Annotation: multiple; solitary = LEIOMYOMA; coord IM with precoord organ/neopl term (IM) if relevant
ID#: D018231

Leiomyosarcoma

Definition: A sarcoma containing large spindle cells of smooth muscle. Although it rarely occurs in soft tissue, it is common in the viscera. It is the most common soft tissue sarcoma of the gastrointestinal tract and uterus. The median age of patients is 60 years. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1865)
Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D007890

Leishmaniasis

Definition: A disease caused by any of a number of species of protozoa in the genus LEISHMANIA. There are four major clinical types of this infection: cutaneous (Old and New World) (LEISHMANIASIS, CUTANEOUS), diffuse cutaneous (LEISHMANIASIS, DIFFUSE CUTANEOUS), mucocutaneous (LEISHMANIASIS, MUCOCUTANEOUS), and visceral (LEISHMANIASIS, VISCERAL).
Annotation: protozoan infect; GEN or unspecified; prefer specifics; American leishmaniasis is LEISHMANIASIS, AMERICAN see LEISHMANIASIS, CUTANEOUS; tegumentary leishmaniasis = LEISHMANIASIS, CUTANEOUS
ID#: D007896

Leishmaniasis, Cutaneous

Definition: An endemic disease that is characterized by the development of single or multiple localized lesions on exposed areas of skin that typically ulcerate. The disease has been divided into Old and New World forms. Old World leishmaniasis is separated into three distinct types according to epidemiology and clinical manifestations and is caused by species of the L. tropica and L. aethiopica complexes as well as by species of the L. major genus. New World leishmaniasis, also called American leishmaniasis, occurs in South and Central America and is caused by species of the L. mexicana or L. braziliensis complexes.
Annotation: caused by L. aethiopica, L. braziliensis, L. major, L. mexicana or L. tropica; LEISHMANIASIS, DIFFUSE CUTANEOUS & LEISHMANIASIS, MUCOCUTANEOUS are also available
ID#: D016773

Leishmaniasis, Diffuse Cutaneous

Definition: A form of LEISHMANIASIS, CUTANEOUS caused by Leishmania aethiopica in Ethiopia and Kenya, L. pifanoi in Venezuela, L. braziliensis in South America, and L. mexicana in Central America. This disease is characterized by massive dissemination of skin lesions without visceral involvement.
Annotation: caused by L. aethiopica, L. braziliensis, L. mexicana or L. pifanoi; see MeSH definition for locales
ID#: D016774

Leishmaniasis, Mucocutaneous

Definition: A disease characterized by the chronic, progressive spread of lesions from New World cutaneous leishmaniasis caused by species of the L. braziliensis complex to the nasal, pharyngeal, and buccal mucosa some time after the appearance of the initial cutaneous lesion. Nasal obstruction and epistaxis are frequent presenting symptoms.
Annotation: caused by Leishmania braziliensis or L. guyanensis
ID#: D007897

Leishmaniasis, Visceral

Definition: A chronic disease caused by LEISHMANIA DONOVANI and transmitted by the bite of several sandflies of the genera Phlebotomus and Lutzomyia. It is commonly characterized by fever, chills, vomiting, anemia, hepatosplenomegaly, leukopenia, hypergammaglobulinemia, emaciation, and an earth-gray color of the skin. The disease is classified into three main types according to geographic distribution: Indian, Mediterranean (or infantile), and African.
Annotation: caused by L. donovani or L. infantum
ID#: D007898

Lens Diseases

Definition:
Annotation: GEN or unspecified only: prefer specifics
ID#: D007905

Lens Subluxation

Definition: Incomplete rupture of the zonule with the displaced lens remaining behind the pupil. In dislocation, or complete rupture, the lens is displaced forward into the anterior chamber or backward into the vitreous body. When congenital, this condition is known as ECTOPIA LENTIS.
Annotation: spontaneous or traumatic; luxation = total disloc, subluxation = partial disloc
ID#: D007906

Lentigo

Definition: Small circumscribed melanoses resembling, but differing histologically from, freckles. The concept includes senile lentigo ('liver spots') and nevoid lentigo (nevus spilus, lentigo simplex) and may also occur in association with multiple congenital defects or congenital syndromes (e.g., Peutz-Jeghers syndrome).
Annotation: a form of melanosis
ID#: D007911

Lentivirus Infections

Definition: Virus diseases caused by the Lentivirus genus. They are multi-organ diseases characterized by long incubation periods and persistent infection.
Annotation: caused by a retrovirus; GEN or unspecified: prefer specifics
ID#: D016180

LEOPARD Syndrome

Definition: A syndrome characterized by Lentigines (LENTIGO); Electrocardiographic conduction abnormalities; Ocular HYPERTELORISM; PULMONARY STENOSIS; Abnormal genitalia; Retardation of growth; and Deafness (HEARING LOSS, SENSORINEURAL). It is caused by mutations of the PTPN11 gene which codes for non-receptor PROTEIN TYROSINE PHOSPHATASE, type 11. The clinical features of LEOPARD syndrome overlap those of NOONAN SYNDROME, also caused by mutations in PTPN11, as well as those of NEUROFIBROMATOSIS 1. The syndrome has also been associated with mutations in the NF1 gene (GENES, NEUROFIBROMATOSIS 1). (J Med Genet 2002 Aug;39(8):571-4)
Annotation:
ID#: D044542

Leprosy

Definition: A chronic granulomatous infection caused by MYCOBACTERIUM LEPRAE. The granulomatous lesions are manifested in the skin, the mucous membranes, and the peripheral nerves. Two polar or principal types are lepromatous and tuberculoid.
Annotation: caused by Mycobacterium leprae; GEN or unspecified: prefer specifics; rat leprosy = MYCOBACTERIUM INFECTIONS (IM) + MYCOBACTERIUM LEPRAEMURIUM (IM); /drug ther: consider also LEPROSTATIC AGENTS; ENL (erythema nodosum leprosum): see note at LEPROSY, LEPROMATOUS
ID#: D007918

Leprosy, Borderline

Definition: A form of LEPROSY in which there are clinical manifestations of both principal types (lepromatous and tuberculoid). The disease may shift toward one of these two polar or principal forms.
Annotation:
ID#: D015439

Leprosy, Lepromatous

Definition: A chronic communicable infection which is a principal or polar form of LEPROSY. This disorder is caused by MYCOBACTERIUM LEPRAE and produces diffuse granulomatous skin lesions in the form of nodules, macules, or papules. The peripheral nerves are involved symmetrically and neural sequelae occur in the advanced stage.
Annotation: erythema nodosum leprosum (ENL): index under LEPROSY, LEPROMATOUS (IM) + ERYTHEMA NODOSUM (IM)
ID#: D015440

Leprosy, Tuberculoid

Definition: A principal or polar form of LEPROSY in which the skin lesions are few and are sharply demarcated. Peripheral nerve involvement is pronounced and may be severe. Unlike lepromatous leprosy (LEPROSY, LEPROMATOUS), the lepromin test is positive. Tuberculoid leprosy is rarely a source of infection to others.
Annotation:
ID#: D015441

Leptospirosis

Definition: Infections with bacteria of the genus LEPTOSPIRA.
Annotation: gram-neg bact infect; a spirochete infect
ID#: D007922

Leriche's Syndrome

Definition: A syndrome caused by obstruction of the terminal aorta. It usually occurs in males and is characterized by fatigue in the hips, thighs, or calves on exercising, absence of pulsation in the femoral arteries, impotence, and often pallor and coldness of the lower limbs. (From Dorland, 27th ed)
Annotation: obstruction of terminal aorta
ID#: D007925

Lesch-Nyhan Syndrome

Definition: An inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism; HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE. Affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. Self-destructive behaviors such as biting of fingers and lips are seen frequently. Intellectual impairment may also occur but is typically not severe. Elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. (Menkes, Textbook of Child Neurology, 5th ed, pp127)
Annotation:
ID#: D007926

Letterer-Siwe Disease

Definition: Acute, disseminated, rapidly progressive form of Langerhans-cell histiocytosis.
Annotation: a Langerhans-cell histiocytosis
ID#: D007929

Leukemia

Definition: A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. It is classified according to degree of cell differentiation as acute or chronic, and according to predominant type of cell involved as myelogenous or lymphocytic. (Dorland, 28th ed)
Annotation: note all the leukemia terms & cross-refs for the many types of leukemia; if not here, check Tumor Manual or Tumor Key; do not use /blood supply /chem /second /secret /ultrastruct; radiation-induced = LEUKEMIA, RADIATION-INDUCED; leukemic infiltration = LEUKEMIC INFILTRATION but see note there
ID#: D007938

Leukemia L1210

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct /vet
ID#: D007939

Leukemia L5178

Definition: An experimental lymphocytic leukemia of mice.
Annotation: do not use /blood supply /chem /second /secret /ultrastruct /vet
ID#: D007940

Leukemia P388

Definition: An experimental lymphocytic leukemia originally induced in DBA/2 mice by painting with methylcholanthrene.
Annotation:
ID#: D007941

Leukemia, B-Cell

Definition:
Annotation: GEN or unspecified: prefer specifics; do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015448

Leukemia, B-Cell, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; DF: note short X ref B-ALL
ID#: D015450

Leukemia, B-Cell, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015451

Leukemia, Basophilic, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015471

Leukemia, CALLA-Positive

Definition: Acute leukemia in which lymphocytes are positive for the common acute lymphoblastic leukemia antigen (CALLA).
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; CALLA stands for "common acute lymphoblastic leukemia antigen" or "common ALL antigen" ( = CALLA see NEPRILYSIN)
ID#: D015453

Leukemia, Eosinophilic, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015472

Leukemia, Erythroblastic, Acute

Definition: A myeloproliferative disorder characterized by neoplastic proliferation of erythroblastic and myeloblastic elements with atypical erythroblasts and myeloblasts in the peripheral blood.
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; Friend erythroleukemia cells: coord IM with FRIEND MURINE LEUKEMIA VIRUS (IM) + TUMOR CELLS, CULTURED (NIM)
ID#: D004915

Leukemia, Experimental

Definition: Leukemia induced experimentally by administration of various leukemogenic agents, viruses, radiation or transplantation.
Annotation: includes infection by oncogenic leukoviruses or leukemia viruses (NIM); do not use /blood supply /chem /second /secret /ultrastruct; DF: LEUKEMIA EXPER
ID#: D007942

Leukemia, Feline

Definition: A neoplastic disease of cats frequently associated with feline leukemia virus infection.
Annotation: caused by a retrovirus; don't forget also CATS (NIM) & check tag ANIMALS
ID#: D016582

Leukemia, Hairy Cell

Definition: A neoplastic disease of the lymphoreticular cells which is considered to be a rare type of chronic leukemia; it is characterized by an insidious onset, splenomegaly, anemia, granulocytopenia, thrombocytopenia, little or no lymphadenopathy, and the presence of "hairy" or "flagellated" cells in the blood and bone marrow.
Annotation: "hairy" refers to flagellated appearance of the lymphoreticular cells; since the dis is chronic, do not coord with CHRONIC DISEASE; do not use /blood supply /chem /second /secret /ultrastruct; consider also LEUKEMIA, T-CELL, HTLV-II-ASSOCIATED
ID#: D007943

Leukemia, Lymphocytic

Definition: Leukemia associated with hyperplasia and overactivity of the lymphoid tissue. There are increased numbers of circulating malignant lymphocytes and lymphoblasts. (Dorland, 28th ed, p919)
Annotation: GEN or unspecified: prefer specifics; do not use /blood supply /chem /second /secret /ultrastruct
ID#: D007945

Leukemia, Lymphocytic, Acute

Definition: Lymphocytic leukemia where cells show little differentiation. There are three major subgroups (FAB L1, L2, & L3) based on distinguishing characteristics of the blast cells. Adult and childhood forms of the disease show biological differences as well.
Annotation: GEN or unspecified: prefer specifics
ID#: D015447

Leukemia, Lymphocytic, Acute, L1

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; don't forget CHILD check tags; DF: note short X ref ALL, CHILDHOOD
ID#: D015454

Leukemia, Lymphocytic, Acute, L2

Definition:
Annotation: note X ref on Philadelphia-positive: LEUKEMIA, MYELOID, PHILADELPHIA-POSITIVE is also available; do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015455

Leukemia, Lymphocytic, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015462

Leukemia, Mast-Cell

Definition: A form of systemic mastocytosis (MASTOCYTOSIS, SYSTEMIC) characterized by the presence of large numbers of tissue MAST CELLS in the peripheral blood without skin lesions. It is a high-grade LEUKEMIA disease with bone marrow smear of >20% MAST CELLS, multi-organ failure and a short survival.
Annotation:
ID#: D007946

Leukemia, Megakaryocytic, Acute

Definition: Nonlymphocytic leukemia in which 20-30% of the bone marrow or peripheral blood cells are of megakaryocyte lineage. Myelofibrosis or increased bone marrow reticulin is common.
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D007947

Leukemia, Mixed-Cell

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015456

Leukemia, Monocytic, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D007948

Leukemia, Monocytic, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015476

Leukemia, Myelocytic, Acute

Definition: Progressive, malignant disease of the myeloid tissue in which the granular, polymorphonuclear leukocytes and their precursors predominate.
Annotation: GEN; note X refs for when specified as M1 or M2; for M3-M7 use MeSH see refs at LEUKEMIA, MYELOID, ACUTE, M3, etc., but when author uses term "acute myeloid leukemia" without specifying M1-M7, index under LEUKEMIA, MYELOID (IM) + ACUTE DISEASE (NIM); do not use /blood supply /chem /second /secret /ultrastruct
ID#: D007950

Leukemia, Myeloid

Definition: Form of leukemia characterized by an uncontrolled proliferation of the myeloid lineage and their precursors in the bone marrow and other sites.
Annotation: GEN or unspecified: prefer specifics; do not use /blood supply /chem /second /secret /ultrastruct
ID#: D007951

Leukemia, Myeloid, Aggressive-Phase

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; DF: CML AGGRESSIVE
ID#: D015465

Leukemia, Myeloid, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015464

Leukemia, Myeloid, Chronic-Phase

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; DF: CML CHRONIC
ID#: D015466

Leukemia, Myeloid, Philadelphia-Negative

Definition:
Annotation: "Philadelphia" refers to the Philadelphia chromosome; do not use /blood supply /chem /second /secret /ultrastruct; DF: LEUKEMIA PHILA NEG
ID#: D015468

Leukemia, Myeloid, Philadelphia-Positive

Definition:
Annotation: "Philadelphia" refers to the Philadelphia chromosome; do not use /blood supply /chem /second /secret /ultrastruct; DF: LEUKEMIA PHILA POS
ID#: D015469

Leukemia, Myelomonocytic, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015479

Leukemia, Myelomonocytic, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015477

Leukemia, Neutrophilic, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015467

Leukemia, Nonlymphocytic, Acute

Definition: Acute leukemia distinguished from acute lymphocytic leukemia (ALL) by the morphology of the marrow and blood leukemic cells. Cytoplasmic granules are usually present and the nucleus is usually large and irregular. ANLL is more common in adults than ALL and occurs at any age.
Annotation: GEN or unspecified: prefer specifics; do not use /blood supply /chem /second /secret /ultrastruct; DF: note short X ref ANLL
ID#: D015470

Leukemia, Null-Cell

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015457

Leukemia, Plasmacytic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D007952

Leukemia, Pre-B-Cell

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015452

Leukemia, Prolymphocytic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015463

Leukemia, Promyelocytic, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015473

Leukemia, Radiation-Induced

Definition:
Annotation: coord IM with specific type of LEUKEMIA (IM); do not use /blood supply /chem /second /secret /ultrastruct; policy: Manual 24.4.3.2
ID#: D007953

Leukemia, Subleukemic

Definition: A form of leukemia that occurs without elevated levels of leukocytes within the blood. Lesions containing abnormal leukocytes can be found within tissues.
Annotation: coord IM with specific type of LEUKEMIA (IM)
ID#: D007954

Leukemia, T-Cell

Definition: A subtype of lymphocytic leukemia classified as acute or chronic depending on the degree of cell differentiation, not the duration of the disease.
Annotation: GEN or unspecified: prefer specifics
ID#: D015458

Leukemia, T-Cell, Acute

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct; DF: note short X ref T-ALL
ID#: D015459

Leukemia, T-Cell, Chronic

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015461

Leukemia, T-Cell, HTLV-II-Associated

Definition:
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D015446

Leukemia-Lymphoma, T-Cell, Acute, HTLV-I-Associated

Definition: Aggressive T-Cell malignancy with adult onset, caused by HUMAN T-LYMPHOTROPIC VIRUS 1. It is endemic in Japan, the Caribbean basin, Southeastern United States, Hawaii, and parts of Central and South America and sub-Saharan Africa.
Annotation:
ID#: D015460

Leukemic Infiltration

Definition: A pathologic change in leukemia in which leukemic cells permeate various organs at any stage of the disease. All types of leukemia show various degrees of infiltration, depending upon the type of leukemia. The degree of infiltration may vary from site to site. The liver and spleen are common sites of infiltration, the greatest appearing in myelocytic leukemia, but infiltration is seen also in the granulocytic and lymphocytic types. The kidney is also a common site and of the gastrointestinal system, the stomach and ileum are commonly involved. In lymphocytic leukemia the skin is often infiltrated. The central nervous system too is a common site.
Annotation: IM; coord with organ /pathol (IM) (not the precoord organ/neopl term) + the specific type of leukemia /pathol (IM), as "leukemic infiltration of the skin in lymphocytic leukemia" = LEUKEMIC INFILTRATION (IM) + SKIN /pathol (IM) (not SKIN NEOPLASMS) + LEUKEMIA, LYMPHOCYTIC /pathol (IM); Manual 24.4.1.2
ID#: D017254

Leukemoid Reaction

Definition: A peripheral blood picture resembling that of leukemia or indistinguishable from it on the basis of morphologic appearance alone. (Dorland, 27th ed)
Annotation: extreme leukocytosis resembling leukemia
ID#: D007955

Leukocyte Disorders

Definition: Disordered formation of various types of leukocytes or an abnormal accumulation or deficiency of these cells.
Annotation: GEN or unspecified; prefer specifics; DF: LEUKOCYTE DIS
ID#: D007960

Leukocyte-Adhesion Deficiency Syndrome

Definition: Rare, autosomal recessive disorder caused by deficiency of the beta 2 integrin receptors (RECEPTORS, LEUKOCYTE-ADHESION) comprising the CD11/CD18 family of glycoproteins. The syndrome is characterized by abnormal adhesion-dependent functions, especially defective tissue emigration of neutrophils, leading to recurrent infection.
Annotation: an immunol defic syndrome; DF: LEUKOCYTE ADHESION DEFIC SYNDROME
ID#: D018370

Leukocytosis

Definition: A transient increase in the number of leukocytes in a body fluid.
Annotation: coord with type of white cell and body fluid, using available subheadings when appropriate
ID#: D007964

Leukodystrophy, Globoid Cell

Definition: An autosomal recessive inherited sphingolipidosis caused by a deficiency of GALACTOSYLCERAMIDASE leading to an accumulation of PSYCHOSINE in LYSOSOMES of the BRAIN; PERIPHERAL NERVES; LIVER; KIDNEY; and LEUKOCYTES. In the nervous sytem there is prominent central and peripheral demyelination. The infantile form presents at age 4-6 months with psychomotor retardation, MUSCLE SPASTICITY, and tonic spasms induced by minor stimuli. Death occurs within two years. Later onset forms of this disease are characterized by a less fulminant course. (From Menkes, Textbook of Child Neurology, 5th ed, pp195-7)
Annotation:
ID#: D007965

Leukodystrophy, Metachromatic

Definition: An autosomal recessive lysosomal storage disease caused by a deficiency of CEREBROSIDE-SULFATASE leading to an accumulation of cerebroside sulfate in the nervous system and other organs. Pathologic features include diffuse demyelination and metachromatically-staining granules within glial cells, macrophages, and free in tissue. Clinical subtypes include late infantile, juvenile, and adult forms. The late infantile form presents at 12-18 months of age with progressive psychomotor retardation, ATAXIA, spasticity, and OPTIC ATROPHY. The juvenile form has onset at 4-12 years and features behavioral alterations and ataxia followed by spasticity, DEMENTIA, and visual loss. The adult form presents in the second decade or later with psychiatric manifestations, gait difficulties, and less often as a peripheral neuropathy. (From Menkes, Textbook of Child Neurology, 5th ed, pp192-5)
Annotation:
ID#: D007966

Leukoedema, Oral

Definition: A disorder of the buccal mucosa resembling early leukoplakia, characterized by the presence of filmy opalescence of the mucosa in the early stages to a whitish gray cast with a coarsely wrinkled surface in the later stages, associated with intracellular edema of the spinous or malpighian layer. (Dorland, 27th ed)
Annotation: disord of buccal mucosa
ID#: D007967

Leukoencephalitis, Acute Hemorrhagic

Definition: A fulminant and often fatal demyelinating disease of the brain which primarily affects young adults and children. Clinical features include the rapid onset of weakness, SEIZURES, and COMA. It may follow a viral illness or MYCOPLASMA PNEUMONIAE infections but in most instances there is no precipitating event. Pathologic examination reveals marked perivascular demyelination and necrosis of white matter with microhemorrhages. (Adams et al., Principles of Neurology, 6th ed, pp924-5)
Annotation: DF: LEUKOENCEPH ACUTE HEMOR
ID#: D004684

Leukoencephalopathy, Progressive Multifocal

Definition: An opportunistic viral infection of the central nervous system associated with conditions that impair cell-mediated immunity (e.g., ACQUIRED IMMUNODEFICIENCY SYNDROME and other IMMUNOLOGIC DEFICIENCY SYNDROMES; HEMATOLOGIC NEOPLASMS; IMMUNOSUPPRESSION; and COLLAGEN DISEASES). The causative organism is JC Polyomavirus (JC VIRUS) which primarily affects oligodendrocytes, resulting in multiple areas of demyelination. Clinical manifestations include DEMENTIA; ATAXIA; visual disturbances; and other focal neurologic deficits, generally progressing to a vegetative state within 6 months. (From Joynt, Clinical Neurology, 1996, Ch26, pp36-7)
Annotation: DF: LEUKOENCEPH PROGRESSIVE MULTIFOCAL
ID#: D007968

Leukomalacia, Periventricular

Definition: Degeneration of white matter adjacent to the CEREBRAL VENTRICLES following cerebral hypoxia or BRAIN ISCHEMIA in neonates. The condition primarily affects white matter in the perfusion zone between superficial and deep branches of the MIDDLE CEREBRAL ARTERY. Clinical manifestations include VISION DISORDERS; CEREBRAL PALSY; PARAPLEGIA; SEIZURES; and COGNITIVE DISORDERS. (From Adams et al., Principles of Neurology, 6th ed, p1021; Joynt, Clinical Neurology, 1997, Ch4, pp30-1)
Annotation: periventricular refers to the cerebral ventricles
ID#: D007969

Leukopenia

Definition:
Annotation: decrease in no. of leukocytes
ID#: D007970

Leukoplakia

Definition: A white patch on a mucous membrane that will not rub off. (Dorland, 27th ed)
Annotation: a precancerous condition; coord IM with organ /neoplasms term (IM)
ID#: D007971

Leukoplakia, Hairy

Definition: Epithelial hyperplasia of the oral mucosa associated with Epstein-Barr virus (HERPESVIRUS 4, HUMAN) and found almost exclusively in persons with HIV infection. The lesion consists of a white patch that is often corrugated or hairy.
Annotation: a form of oral leukoplakia seen in HIV infect; do not confuse with TONGUE, HAIRY
ID#: D017733

Leukoplakia, Oral

Definition: A white patch seen on the oral mucosa. It is considered a premalignant condition and is often tobacco-induced. When evidence of Epstein-Barr virus is present, the condition is called hairy leukoplakia (LEUKOPLAKIA, HAIRY).
Annotation: neoplastic; /blood supply /chem /secret /ultrastruct permitted
ID#: D007972

Leukorrhea

Definition: A whitish, viscid discharge from the vagina and uterine cavity. (Dorland, 27th ed)
Annotation: white vaginal discharge
ID#: D007973

Leukostasis

Definition: Abnormal intravascular leukocyte aggregation and clumping often seen in leukemia patients. The brain and lungs are the two most commonly affected organs. This acute syndrome requires aggressive cytoreductive modalities including chemotherapy and/or leukophoresis. It is differentiated from LEUKEMIC INFILTRATION which is a neoplastic process where leukemic cells invade organs.
Annotation: note category: abnorm intravasc leukocyte aggreg
ID#: D018921

Levocardia

Definition: Location of heart in left hemithorax with apex pointing to the left, but with situs inversus of other viscera and defects of the heart, or corrected transposition of great vessels.
Annotation: heart in left hemithorax; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D007979

Lewy Body Disease

Definition: A neurodegenerative disease characterized by dementia, mild parkinsonism, and fluctuations in attention and alertness. The neuropsychiatric manifestations tend to precede the onset of bradykinesia, MUSCLE RIGIDITY, and other extrapyramidal signs. DELUSIONS and visual HALLUCINATIONS are relatively frequent in this condition. Histologic examination reveals LEWY BODIES in the CEREBRAL CORTEX and BRAIN STEM. SENILE PLAQUES and other pathologic features characteristic of ALZHEIMER DISEASE may also be present. (From Neurology 1997;48:376-380; Neurology 1996;47:1113-1124)
Annotation: LEWY BODY PARKINSON DISEASE see PARKINSON DISEASE is also available
ID#: D020961

Leydig Cell Tumor

Definition: The most common nongerminal tumor of the testis, derived from the Leydig cells. It is rarely malignant. This tumor appears among 1-3% of testicular tumors and although they may be seen in children, the median age of appearance is 60 years. They are sometimes seen in women as ovarian tumors. Clinically, symptoms are usually related to the endocrine abnormalities induced by this tumor. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1597)
Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with TESTICULAR NEOPLASMS (IM) in male or OVARIAN NEOPLASMS (IM) if in female
ID#: D007984

Li-Fraumeni Syndrome

Definition: Rare autosomal dominant syndrome characterized by mesenchymal and epithelial neoplasms at multiple sites. A point mutation of the p53 tumor suppressor gene apparently predisposes family members who inherit it to develop certain cancers.
Annotation: a multiple neopl syndrome; do not use /blood supply /chem /congen /second /secret /ultrastruct
ID#: D016864

Lice Infestations

Definition: Parasitic attack or subsistence on the skin by members of the order Phthiraptera, especially on humans by Pediculus humanus of the family Pediculidae. The hair of the head, eyelashes, and pubis is a frequent site of infestation. (From Dorland, 28th ed; Stedman, 26th ed)
Annotation: coord IM with specific louse (IM); head lice: coord IM with SCALP DERMATOSES (IM) and PEDICULUS (IM)
ID#: D010373

Lichen Nitidus

Definition: A chronic inflammatory disease characterized by shiny, flat-topped, usually flesh-colored micropapules no larger than the head of a pin. Lesions are localized in the early stages, found chiefly on the lower abdomen, penis, and inner surface of the thighs. Distribution may become generalized as the disease progresses.
Annotation: a skin dis, not a plant
ID#: D017513

Lichen Planus

Definition: An inflammatory, pruritic disease of the skin and mucous membranes, which can be either generalized or localized. It is characterized by distinctive purplish, flat-topped papules having a predilection for the trunk and flexor surfaces. The lesions may be discrete or coalesce to form plaques. Histologically, there is a "saw-tooth" pattern of epidermal hyperplasia and vacuolar alteration of the basal layer of the epidermis along with an intense upper dermal inflammatory infiltrate composed predominantly of T-cells. Etiology is unknown.
Annotation: a skin dis; sometimes called simply "lichen": check text & its bibliog; lichen planus atrophicus: index here & do not confuse with LICHEN SCLEROSUS ET ATROPHICUS
ID#: D008010

Lichen Planus, Oral

Definition: Oral lesions accompanying cutaneous lichen planus or often occurring alone. The buccal mucosa, lips, gingivae, floor of the mouth, and palate are usually affected (in a descending order of frequency). Typically, oral lesions consist of radiating white or gray, velvety, threadlike lines, arranged in a reticular pattern, at the intersection of which there may be minute, white, elevated dots or streaks (Wickham's striae). (Jablonski, Illustrated Dictionary of Dentistry)
Annotation: alone or with cutaneous lichen planus
ID#: D017676

Lichen Sclerosus et Atrophicus

Definition: A chronic, atrophic skin disease characterized by white, angular, flat, well-defined, indurated papules with an erythematous halo and follicular, black, keratotic plugs. It is the most common cause of kraurosis vulvae in females and balanitis xerotica obliterans in males. It is called also white spot disease and Csillag's disease. (Dorland, 27th ed)
Annotation: a skin dis; do not confuse with lichen planus atrophicus (index under LICHEN PLANUS); DF: note short X ref
ID#: D018459

Lichenoid Eruptions

Definition: Conditions in which there is histological damage to the lower epidermis along with a grouped chronic inflammatory infiltrate in the papillary dermis disturbing the interface between the epidermis and dermis. LICHEN PLANUS is the prototype of all lichenoid eruptions. (From Rook et al., Textbook of Dermatology, 4th ed, p398)
Annotation: GEN or unspecified; prefer specifics
ID#: D017512

Lightning Injuries

Definition: Accidental injuries caused by brief high-voltage electrical discharges during thunderstorms. Cardiopulmonary arrest, coma and other neurologic symptoms, myocardial necrosis, and dermal burns are common. Prompt treatment of the acute sequelae, including cardiopulmonary resuscitation, is indicated for survival.
Annotation: DF: LIGHTNING INJ
ID#: D015168

Limb Deformities, Congenital

Definition: Congenital structural deformities of the upper and lower extremities collectively or unspecified.
Annotation: GEN or unspecified; prefer ARM or its parts /abnorm or its specifics & LEG or its parts /abnorm or its specifics; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; DF: LIMB DEFORMITIES CONGEN
ID#: D017880

Limbic Encephalitis

Definition: A paraneoplastic syndrome marked by degeneration of neurons in the medial temporal lobe. Clinical features include behavioral changes, HALLUCINATIONS, loss of short term memory, anosmia, AGEUSIA, and DEMENTIA. Circulating anti-neuronal antibodies (anti-Hu; also called ANNA 1) and small cell lung carcinomas are frequently associated with this condition. (From Pathologe 1997 Sep;18(5):406-10; J Int Neuropsychol Soc 1996 Sep;2(5):460-6; Brain 1997 Jun;120(Pt 6):923-8)
Annotation: DF: LIMBIC ENCEPH
ID#: D020363

Linitis Plastica

Definition: A condition where the stomach wall becomes thickened, rubbery and loses its ability to distend. The stomach assumes a "leather bottle" shape. It is most often seen in adenocarcinoma of the stomach. The term is often used synonymously with diffuse adenocarcinoma of the stomach.
Annotation: neoplastic; /blood supply /chem /second /secret /ultrastruct permitted; coord IM with STOMACH NEOPLASMS (IM)
ID#: D008039

Lip Diseases

Definition:
Annotation: inflamm dis = CHEILITIS
ID#: D008047

Lip Neoplasms

Definition: Tumors or cancer of the LIP.
Annotation: coord IM with histol type of neopl (IM)
ID#: D008048

Lipid Metabolism, Inborn Errors

Definition:
Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; coord IM with specific lipid /metab (IM); DF: LIPID METAB INBORN ERR
ID#: D008052

Lipodystrophy

Definition: A collection of rare conditions resulting from defective fat metabolism and characterized by atrophy of the subcutaneous fat. They include total, congenital or acquired, partial, abdominal infantile, and localized lipodystrophy.
Annotation: atrophy of subcutaneous fat
ID#: D008060

Lipoidosis

Definition: A disturbance of lipid metabolism with abnormal deposit of lipids in the cells. (Dorland, 27th ed)
Annotation: an inborn error of lipid metab; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D008064

Lipoidproteinosis

Definition: A familial disease occurring in the course of latent diabetes, marked by yellowish nodules on the skin and mucosae, keratotic lesions on the extremities, and hoarseness due to faulty lipid metabolism. (Dorland, 27th ed)
Annotation: a lipoidosis; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D008065

Lipoma

Definition: A benign tumor composed of fat cells.
Annotation: solitary; multiple = LIPOMATOSIS; coord IM with precoord organ/neopl term (IM)
ID#: D008067

Lipomatosis

Definition: A disorder consisting of the accumulation of abnormal localized, or tumor-like fat in the tissues.
Annotation: solitary is probably LIPOMA which is neoplastic; do not use /blood supply /chem /second /secret /ultrastruct; coord IM with precoord organ/dis term (IM) if relevant; LIPOMATOSIS, MULTIPLE SYMMETRICAL is also available
ID#: D008068

Lipomatosis, Multiple Symmetrical

Definition: Multiple circumscribed or encapsulated lipomas which may be distributed symmetrically or haphazardly or which may form a collar around the neck.
Annotation: do not use /blood supply /chem /second /secret /ultrastruct
ID#: D008069

Lipoprotein Lipase Deficiency, Familial

Definition: A rare familial condition characterized by massive chylomicronemia and decreased levels of other lipoproteins. It is due to deficiency of lipoprotein lipase, an alkaline triglyceride hydrolase which catalyzes an important step in the extrahepatic removal of triglyceride-rich lipoproteins from the blood.
Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D008072

Liposarcoma

Definition: A malignant tumor derived from primitive or embryonal lipoblastic cells. It may be composed of well-differentiated fat cells or may be dedifferentiated: myxoid (LIPOSARCOMA, MYXOID), round-celled, or pleomorphic, usually in association with a rich network of capillaries. Recurrences are common and dedifferentiated liposarcomas metastasize to the lungs or serosal surfaces. (From Dorland, 27th ed; Stedman, 25th ed)
Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D008080

Liposarcoma, Myxoid

Definition: A liposarcoma containing myxomatous tissue. (Dorland, 27th ed)
Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D018208

Listeria Infections

Definition: Infections with bacteria of the genus LISTERIA.
Annotation: gram-pos bact infect; Listeria monocytogenes infection = LISTERIA INFECTIONS & do not bother to coord with LISTERIA MONOCYTOGENES; MENINGITIS, LISTERIA is available
ID#: D008088

Lithiasis

Definition: A condition characterized by the formation of CALCULI and concretions in the hollow organs or ducts of the body. They occur most often in the gallbladder, kidney, and lower urinary tract.
Annotation: prefer specifics; coord IM with organ /disease term (IM)
ID#: D020347

Liver Abscess

Definition: Solitary or multiple collections of pus within the liver. It is usually associated with systemic manifestations of toxemia and clinical signs of disease in the right upper quadrant of the abdomen. It was known in ancient times to Hippocrates and Celsus. (Bockus, Gastroenterology, 4th ed, p3288-9)
Annotation: for coord read note on ABSCESS; LIVER ABSCESS, AMEBIC is also available
ID#: D008100

Liver Abscess, Amebic

Definition: Liver abscess caused by ENTAMOEBA HISTOLYTICA.
Annotation: amebic infect of liver caused by Entamoeba histolytica
ID#: D008101

Liver Cirrhosis

Definition: Liver disease in which the normal microcirculation, the gross vascular anatomy, and the hepatic architecture have been variably destroyed and altered with fibrous septa surrounding regenerated or regenerating parenchymal nodules.
Annotation: do not index ascites unless specifically pertinent
ID#: D008103

Liver Cirrhosis, Alcoholic

Definition: Liver cirrhosis in alcoholics.
Annotation:
ID#: D008104

Liver Cirrhosis, Biliary

Definition: Liver cirrhosis due to impairment in intrahepatic bile flow. It includes primary biliary cirrhosis affecting bile secretion, and secondary biliary cirrhosis produced by prolonged mechanical obstruction of large intrahepatic or extrahepatic bile ducts.
Annotation:
ID#: D008105

Liver Cirrhosis, Experimental

Definition:
Annotation: DF: LIVER CIRRHOSIS EXPER
ID#: D008106

Liver Diseases

Definition:
Annotation: GEN: prefer specifics; inflamm dis = HEPATITIS & its specifics; /chem ind permitted but consider also HEPATITIS, TOXIC; specialty is HEPATOLOGY see GASTROENTEROLOGY; be careful: do not confuse "hepatic dis" with "intrahepatic dis": "intrahepatic dis" may refer to BILE DUCT DISEASES with regard to BILE DUCTS, INTRAHEPATIC, not LIVER DISEASES
ID#: D008107

Liver Diseases, Alcoholic

Definition: Liver diseases associated with alcoholism. It usually refers to the coexistence of two or more subentities, i.e., alcoholic fatty liver, alcoholic hepatitis, and alcoholic liver cirrhosis, but may be the general entity when subentities are not specified.
Annotation: GEN: specifics FATTY LIVER, ALCOHOLIC; HEPATITIS, ALCOHOLIC & LIVER CIRRHOSIS, ALCOHOLIC are available
ID#: D008108

Liver Diseases, Parasitic

Definition: Infections of the liver with a parasite. They are caused most commonly by trematodes (flukes).
Annotation: coord IM with specific parasitic dis (IM) but note that also available are ECHINOCOCCOSIS, HEPATIC; FASCIOLIASIS & LIVER ABSCESS, AMEBIC
ID#: D008109

Liver Failure

Definition: Severe inability of the liver to function normally, as evidenced by severe jaundice and abnormal levels of ammonia, bilirubin, alkaline phosphatase, glutamic oxaloacetic transaminase, lactic dehydrogenase, and reversal of the albumin/globulin ratio. (Blakiston's Gould Medical Dictionary, 4th ed)
Annotation: if coma is present, index under HEPATIC ENCEPHALOPATHY
ID#: D017093

Liver Failure, Acute

Definition: A form of liver failure with rapid onset. It is often induced by the toxic effect of drugs and various toxic substances in experimental studies in animals and in clinical states in humans. If coma ensues, the constellation of neurological symptoms is referred to as HEPATIC ENCEPHALOPATHY.
Annotation: if coma is present, index under HEPATIC ENCEPHALOPATHY
ID#: D017114

Liver Neoplasms

Definition: Tumors or cancer of the LIVER.
Annotation: coord IM with histol type of neopl (IM), including HEPATOMA (IM); LIVER NEOPLASMS, EXPERIMENTAL is available; be careful: do not confuse "hepatic neopl" with "intrahepatic neopl": "intrahepatic neopl" may refer to BILE DUCT NEOPLASMS with regard to BILE DUCTS, INTRAHEPATIC, not LIVER NEOPLASMS
ID#: D008113

Liver Neoplasms, Experimental

Definition: Experimentally induced tumors of the LIVER.
Annotation: animal only; don't forget check tag ANIMALS; DF: LIVER NEOPL EXPER
ID#: D008114

Loiasis

Definition: A parasitic infection caused by the nematode Loa loa. The vector in the transmission of this infection is the horsefly (Tabanus) or the deerfly or mango fly (Chrysops). The larvae may be seen just beneath the skin or passing through the conjunctiva. Eye lesions are not uncommon. The disease is generally mild and painless.
Annotation: /drug ther: consider FILARICIDES
ID#: D008118

Long QT Syndrome

Definition: A syndrome characterized by history of syncopal episodes and a long QT interval, sometimes leading to sudden death (DEATH, SUDDEN, CARDIAC) due to paroxysmal ventricular arrhythmia. A form associated with autosomal recessive inheritance and congenital deafness is called the JERVELL-LANGE NIELSEN SYNDROME. An autosomal dominant form without deafness is called the ROMANO-WARD SYNDROME.
Annotation:
ID#: D008133

Lordosis

Definition: The anterior concavity in the curvature of the lumbar and cervical spine as viewed from the side. The term usually refers to abnormally increased curvature (hollow back, saddle back, swayback). It does not include lordosis as normal mating posture in certain animals ( = POSTURE + SEX BEHAVIOR, ANIMAL).
Annotation: a type of spinal curvature; disease only; for normal lordosis index under SPINE; for lordosis in animal sex exper use POSTURE + SEX BEHAVIOR, ANIMAL
ID#: D008141

Louping Ill

Definition: An acute tick-borne arbovirus infection causing meningoencephalomyelitis of sheep.
Annotation: caused by a tick-transm flavivirus; usually animal, generally sheep; "louping" is Scottish dialect for "leaping" with ref to musc manifest of infected animal; check tag ANIMALS; don't forget also SHEEP (NIM) but do not index under SHEEP DISEASES
ID#: D008146

Low Back Pain

Definition: Acute or chronic pain in the lumbar or sacral regions, which may be associated with musculo-ligamentous SPRAINS AND STRAINS; INTERVERTEBRAL DISK DISPLACEMENT; and other conditions.
Annotation: "lombo-sciatique" in French texts is indexed here (IM) + SCIATICA (IM)
ID#: D017116

Lower Extremity Deformities, Congenital

Definition: Congenital structural abnormalities of the LOWER EXTREMITY.
Annotation:
ID#: D038061

Lown-Ganong-Levine Syndrome

Definition: A form of pre-excitation characterized by a short PR interval associated with a normal QRS complex.
Annotation: note X ref: normal PR interval & long QRS interval = PRE-EXCITATION, MAHAIN TYPE
ID#: D008151

Ludwig's Angina

Definition: Severe cellulitis of the submaxillary space with secondary involvement of the sublingual and submental space. It usually results from infection in the lower molar area or from a penetrating injury to the mouth floor. (From Dorland, 27th ed)
Annotation: submaxillary cellulitis
ID#: D008158

Lumpy Skin Disease

Definition: A poxvirus infection of cattle characterized by the appearance of nodules on all parts of the skin.
Annotation: caused by a poxvirus; usually animal; check tag ANIMALS; don't forget also CATTLE (NIM) but do not index under CATTLE DISEASES
ID#: D008166

Lung Abscess

Definition: A complication of a localized area of pneumonia or when a neoplasm becomes necrotic and contains purulent material that cannot drain easily from the area because of partial or complete bronchial obstruction. (Harrison's Principles of Internal Medicine, 12th ed, p1068)
Annotation: for coord read note on ABSCESS
ID#: D008169

Lung Diseases

Definition:
Annotation: GEN; prefer specifics; inflamm dis = PNEUMONIA; lung collapse = ATELECTASIS
ID#: D008171

Lung Diseases, Fungal

Definition:
Annotation: coord IM with specific fungal disease (IM); ASPERGILLOSIS, ALLERGIC BRONCHOPULMONARY is available
ID#: D008172

Lung Diseases, Interstitial

Definition: A heterogeneous group of noninfectious, nonmalignant disorders of the lower respiratory tract, affecting primarily the alveolar wall structures but also often involving the small airways and blood vessels of the lung parenchyma. "Interstitial" refers to the fact that the interstitium of the alveolar walls is thickened, usually by fibrosis. This group of diseases is usually inflammatory. (Dorland, 27th ed; Wyngarden, Cecil Textbook of Medicine, 19th ed, p396)
Annotation: GEN or unspecified; prefer specifics; DF: LUNG DIS INTERSTITIAL
ID#: D017563

Lung Diseases, Obstructive

Definition: Any disorder marked by persistent obstruction of bronchial air flow.
Annotation: PULMONARY DISEASE, CHRONIC OBSTRUCTIVE and AIRWAY OBSTRUCTION are also available
ID#: D008173

Lung Diseases, Parasitic

Definition: Infections of the lungs with a parasite. They are caused most commonly by nematodes (roundworms).
Annotation: coord IM with specific parasitic disease (IM) but note that available also is ECHINOCOCCOSIS, PULMONARY
ID#: D008174

Lung Neoplasms

Definition: Tumors or cancer of the LUNG.
Annotation: coord IM with histol type of neopl (IM)
ID#: D008175

Lung, Hyperlucent

Definition: Hyperlucency of one lung with decreased size and vascularity of the lung. It is often associated with BRONCHIOLITIS OBLITERANS and with adenovirus infection in childhood.
Annotation: a type of pulm emphysema manifesting as hyperlucency on x-ray
ID#: D019568

Lupus

Definition: A form of cutaneous tuberculosis. It is seen predominantly in women and typically involves the nasal, buccal, and conjunctival mucosa.
Annotation: a type of cutaneous tuberc; do not confuse with LUPUS ERYTHEMATOSUS, CUTANEOUS
ID#: D008177

Lupus Erythematosus, Cutaneous

Definition: A form of lupus erythematosus in which the skin may be the only organ involved or in which skin involvement precedes the spread into other body systems. It has been classified into three forms - acute (= LUPUS ERYTHEMATOSUS, SYSTEMIC with skin lesions), subacute, and chronic (= LUPUS ERYTHEMATOSUS, DISCOID).
Annotation: acute: consider LUPUS ERYTHEMATOSUS, SYSTEMIC if skin lesions are paramount
ID#: D008178

Lupus Erythematosus, Discoid

Definition: A chronic form of cutaneous lupus erythematosus (LUPUS ERYTHEMATOSUS, CUTANEOUS) in which the skin lesions mimic those of the systemic form but in which systemic signs are rare. It is characterized by the presence of discoid skin plaques showing varying degrees of edema, erythema, scaliness, follicular plugging, and skin atrophy. Lesions are surrounded by an elevated erythematous border. The condition typically involves the face and scalp, but widespread dissemination may occur.
Annotation: do not confuse with systemic or disseminated: discoid is usually in dermatol jrnls, systemic in arthritis or rheumat jrnls; when unspecified in title, "discoid" is usually discernible from text or bibliog refs; note X ref: do not confuse with LUPUS ERYTHEMATOSUS, CUTANEOUS
ID#: D008179

Lupus Erythematosus, Systemic

Definition: A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.
Annotation: if not specified as "systemic" it is still probably correct to index here, not also discoid; LUPUS NEPHRITIS is also available; LE CELLS see NEUTROPHILS is also available: use LUPUS ERYTHEMATOSUS, SYSTEMIC /blood or /pathol + NEUTROPHILS for discussion of the LE cells as cells; DF: SLE
ID#: D008180

Lupus Nephritis

Definition: Glomerulonephritis associated with systemic lupus erythematosus. It is classified into four histologic types: mesangial, focal, diffuse, and membranous.
Annotation: "glomerulonephritis associated with systemic lupus erythematosus"
ID#: D008181

Lupus Vasculitis, Central Nervous System

Definition: Disorders of the brain and spinal cord that are associated with LUPUS ERYTHEMATOSUS, SYSTEMIC. Clinical manifestations may include neurobehavioral dysfunction; SEIZURES; cranial neuropathies (see CRANIAL NERVE DISEASES); hypothalamic dysfunction; focal motor deficits; MYELITIS, TRANSVERSE, and other disorders. Pathologic features include multiple microinfarctions involving the CEREBRAL CORTEX; DIENCEPHALON; and BRAIN STEM (see also BRAIN INFARCTION). (From Adams et al., Principles of Neurology, 6th ed, pp858-9)
Annotation:
ID#: D020945

Lutembacher's Syndrome

Definition: A combination of atrial septal defect and mitral stenosis.
Annotation: atrial septal defect with mitral stenosis; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D008185

Luteoma

Definition: A benign ovarian tumor of granulosa or theca-lutein cell origin, producing progesterone effects on the uterine mucosa. (Stedman, 25th ed)
Annotation: coord IM with OVARIAN NEOPLASMS (IM)
ID#: D018311

Lyme Disease

Definition: An infectious disease caused by a spirochete, BORRELIA BURGDORFERI, which is transmitted chiefly by Ixodes dammini (see IXODES) and pacificus ticks in the United States and Ixodes ricinis (see IXODES) in Europe. It is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. The disease was formerly known as Lyme arthritis and first discovered at Old Lyme, Connecticut.
Annotation: coord IM with specific Borrelia (IM)
ID#: D008193

Lyme Neuroborreliosis

Definition: Nervous system infections caused by tick-borne spirochetes of the BORELLIA BORGDORFERI GROUP. The disease may affect elements of the central or peripheral nervous system in isolation or in combination. Common clinical manifestations include a lymphocytic meningitis, cranial neuropathy (most often a facial neuropathy), POLYRADICULOPATHY, and a mild loss of memory and other cognitive functions. Less often more extensive inflammation involving the central nervous system (encephalomyelitis) may occur. In the peripheral nervous system, B. burgdorferi infection is associated with mononeuritis multiplex and polyradiculoneuritis. (From J Neurol Sci 1998 Jan 8;153(2):182-91)
Annotation: coord IM with Borrelia (IM) + specific site/dis term (IM) if pertinent
ID#: D020852

Lymphadenitis

Definition: Inflammation of the lymph nodes.
Annotation: inflamm of lymph nodes: do not confuse with LYMPHANGITIS, inflamm of lymphatic vessels; consider also MESENTERIC LYMPHADENITIS
ID#: D008199

Lymphangiectasis

Definition: A transient dilatation of the lymphatic vessels.
Annotation:
ID#: D008200

Lymphangiectasis, Intestinal

Definition: Dilatation of the intestinal lymphatic system usually caused by an obstruction in the intestinal wall. It may be congenital or acquired and is characterized by DIARRHEA; HYPOPROTEINEMIA; peripheral and/or abdominal EDEMA; and PROTEIN-LOSING ENTEROPATHIES.
Annotation:
ID#: D008201

Lymphangioma

Definition: A benign tumor representing a congenital malformation of the lymphatic system and made up of newly formed lymph-containing vascular spaces and channels. Lymphangioendothelioma is a type of lymphangioma in which endothelial cells are the dominant component. (From Dorland, 27th ed)
Annotation: /blood supply /chem /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D008202

Lymphangioma, Cystic

Definition: A cystic growth originating from lymphatic tissue. It is usually found in the neck, axilla, or groin.
Annotation: coord IM with precoord organ/neopl term (IM)
ID#: D018191

Lymphangiomyoma

Definition: A tumorlike condition characterized by smooth muscle and endothelium proliferation of lymphatic vessels and lymph nodes in the mediastinum and retroperitoneum, also in the lung. It may be manifested by chylous pleural effusion and ascites.
Annotation: solitary; multiple = LYMPHANGIOMYOMATOSIS but see MeSH definition; /blood supply /chem /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D008203

Lymphangiomyomatosis

Definition: A progressive disorder of women of child-bearing age, marked by nodular and diffuse interstitial proliferation of smooth muscle in the lungs, lymph nodes, and thoracic duct. (Dorland, 27th ed)
Annotation: multiple but read MeSH definition; solitary = LYMPHANGIOMYOMA; do not use /blood supply /chem /second /secret /ultrastruct; coord IM with precoord organ/neopl terms (IM) if relevant
ID#: D018192

Lymphangiosarcoma

Definition: A malignant tumor originating from the endothelial cells of lymphatic vessels. Most lymphangiosarcomas arise in an arm secondary to radical mastectomy but they sometimes complicate idiopathic lymphedema. The lymphedema has usually been present for 6 to 10 years before malignant changes develop. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1866)
Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM)
ID#: D008204

Lymphangitis

Definition:
Annotation: inflamm of lymphatic vessels; do not confuse with LYMPHADENITIS, inflamm of lymph nodes
ID#: D008205

Lymphatic Abnormalities

Definition: Congenital or acquired structural abnormalities of the lymphatic system (LYMPHOID TISSUE) including the lymph vessels.
Annotation:
ID#: D044148

Lymphatic Diseases

Definition: Diseases of lymph or lymph vessels.
Annotation: note X ref LYMPHADENOPATHY: unspecified goes here but note LYMPHADENOPATHY SYNDROME see AIDS-RELATED COMPLEX & consider IMMUNOBLASTIC LYMPHADENOPATHY; SEZARY SYNDROME & other specifics indented here; inflamm dis = LYMPHANGITIS
ID#: D008206

Lymphatic Metastasis

Definition: Transfer of a neoplasm from its primary site to lymph nodes or to distant parts of the body by way of the lymphatic system.
Annotation: NIM, no qualif; IM for GEN or lymphatic metastatic process; when IM, qualif permitted; policy on metastases: Manual 24.3.1, 24.4.1.3+, 24.4.1.4
ID#: D008207

Lymphatic Vessel Tumors

Definition: Neoplasms composed of lymphoid tissue, a lattice work of reticular tissue the interspaces of which contain lymphocytes. The concept does not refer to neoplasms located in lymphatic vessels.
Annotation: neoplasms composed of lymphatic tissue, not located in lymphatic tissue: TN 135; /blood supply /chem /second /secret /ultrastruct permitted; coord with precoord organ/neopl term; restricted use: Manual 24.2.2.5
ID#: D018190

Lymphedema

Definition: Edema due to obstruction of lymph vessels or disorders of the lymph nodes.
Annotation: edema of arms or legs caused by obstruct or dis of lymph nodes or vessels; X ref MILROY'S DISEASE goes under LYMPHEDEMA /congen
ID#: D008209

Lymphocele

Definition: Cystic mass containing lymph from diseased lymphatic channels or following surgical trauma or other injury.
Annotation: non-neoplastic; /blood supply /chem /secret /ultrastruct permitted; coord IM with organ/dis term (IM) if relevant
ID#: D008210

Lymphocytic Choriomeningitis

Definition: A form of meningitis caused by LYMPHOCYTIC CHORIOMENINGITIS VIRUS. MICE and other rodents serve as the natural hosts, and infection in humans usually occurs through inhalation or ingestion of infectious particles. Clinical manifestations include an influenza-like syndrome followed by stiff neck, alterations of mentation, ATAXIA, and incontinence. Maternal infections may result in fetal malformations and injury, including neonatal HYDROCEPHALUS, aqueductal stenosis, CHORIORETINITIS, and MICROCEPHALY. (From Joynt, Clinical Neurology, 1996, Ch26, pp1-3)
Annotation:
ID#: D008216

Lymphocytosis

Definition: Excess of normal lymphocytes in the blood or in any effusion.
Annotation: increase in number of lymphocytes
ID#: D008218

Lymphogranuloma Venereum

Definition: Subacute inflammation of the inguinal lymph glands caused by certain immunotypes of CHLAMYDIA TRACHOMATIS. It is a sexually transmitted disease in the U.S. but is more widespread in developing countries. It is distinguished from granuloma venereum (see GRANULOMA INGUINALE), which is caused by Calymmatobacterium granulomatis.
Annotation: caused by Chlamydia trachomatis
ID#: D008219

Lymphoma

Definition: A general term for various neoplastic diseases of the lymphoid tissue.
Annotation: GEN only or unspecified: prefer specific; do not confuse X ref LYMPHOMA, MALIGNANT with LYMPHOGRANULOMA, MALIGNANT see HODGKIN DISEASE; for lymphoma with AIDS, use LYMPHOMA, AIDS-RELATED
ID#: D008223

Lymphoma, AIDS-Related

Definition: B-cell lymphoid tumors that occur in association with AIDS. Patients often present with an advanced stage of disease and highly malignant subtypes including Burkitt lymphoma, immunoblastic large-cell lymphoma, small non-cleaved-cell lymphoma and diffuse large-cell lymphoma. The tumors are often disseminated in unusual extranodal sites and chromosomal abnormalities are frequently present. It is likely that polyclonal B-cell lymphoproliferation in AIDS is a complex result of EBV infection, HIV antigenic stimulation, and T-cell-dependent HIV activation.
Annotation: a B-cell lymphoma but use for any AIDS-related lymphoma; coord IM with specific type of lymphoma (IM); coord with HIV-1 or HIV-2 (IM or NIM) if pertinent; DF: LYMPHOMA AIDS RELAT
ID#: D016483

Lymphoma, B-Cell

Definition: A group of heterogeneous lymphoid tumors generally expressing one or more B-cell antigens or representing malignant transformations of B-lymphocytes.
Annotation: a non-Hodgkin's lymphoma; LYMPHOMA, T-CELL is also available
ID#: D016393

Lymphoma, Diffuse

Definition: Malignant lymphoma in which neoplastic cells diffusely infiltrate the entire lymph node without any definite organized pattern. Patients whose lymphomas present a diffuse pattern generally have a more unfavorable survival outlook than those presenting with a follicular or nodular pattern.
Annotation: a non-Hodgkin's lymphoma
ID#: D016398

Lymphoma, Follicular

Definition: Malignant lymphoma in which the lymphomatous cells are clustered into identifiable nodules within the lymph nodes. The nodules resemble to some extent the germinal centers of lymph node follicles and most likely represent neoplastic proliferation of lymph node-derived follicular center B-lymphocytes. This class of lymphoma usually occurs in older persons, is commonly multinodal, and possibly extranodal. Patients whose lymphomas present a follicular or nodular pattern generally have a more indolent course than those presenting with a diffuse pattern.
Annotation: a non-Hodgkin's lymphoma; DF: LYMPHOMA FOLLIC
ID#: D008224

Lymphoma, High-Grade

Definition: One of the three major prognostic groupings for non-Hodgkin lymphomas as proposed in the Working Formulation of the Non-Hodgkin's Lymphoma Pathologic Classification Project sponsored by the National Cancer Institute (1981). Lymphomas falling within this group have a relatively unfavorable survival potential.
Annotation: a grade of non-Hodgkin's lymphoma; prefer specific; LYMPHOMA, LOW-GRADE & LYMPHOMA, INTERMEDIATE-GRADE & their specifics are also available
ID#: D016395

Lymphoma, Intermediate-Grade

Definition: One of the three major prognostic groupings for non-Hodgkin lymphomas as proposed in the Working Formulation of the Non-Hodgkin's Lymphoma Pathologic Classification Project sponsored by the National Cancer Institute (1981). Lymphomas falling within this group have an intermediate survival potential.
Annotation: a grade of non-Hodgkin's lymphoma; prefer specific; LYMPHOMA, HIGH-GRADE & LYMPHOMA, LOW-GRADE & their specifics are also available
ID#: D016396

Lymphoma, Large-Cell

Definition: The most common aggressive form of non-Hodgkin lymphoma. It occurs in both diffuse and nodular form. The large cells may have cleaved and non-cleaved nuclei.
Annotation: DF: LYMPHOMA LARGE
ID#: D008225

Lymphoma, Large-Cell, Diffuse

Definition: Malignant lymphoma composed of large cells which may be both cleaved and noncleaved. The pattern is predominantly diffuse. Most of these lymphomas represent the malignant counterpart of B-lymphocytes at midstage in the process of differentiation.
Annotation: an intermediate-grade non-Hodgkin's lymphoma; DF: LYMPHOMA LARGE DIFFUSE
ID#: D016403

Lymphoma, Large-Cell, Follicular

Definition: Malignant lymphoma in which the majority of neoplastic cells within the follicles are large cleaved or noncleaved cells. The degree to which the follicular center cells retain their ability to form follicles varies with the state of B-cell transformation.
Annotation: an intermediate-grade non-Hodgkin's lymphoma; DF: LYMPHOMA LARGE FOLLIC
ID#: D016404

Lymphoma, Large-Cell, Immunoblastic

Definition: Malignant lymphoma characterized by the presence of immunoblasts with uniformly round-to-oval nuclei, one or more prominent nucleoli, and abundant cytoplasm. This class may be subdivided into plasmacytoid and clear-cell types based on cytoplasmic characteristics. A third category, pleomorphous, may be analogous to some of the peripheral T-cell lymphomas (LYMPHOMA, T-CELL, PERIPHERAL) recorded in both the United States and Japan.
Annotation: a diffuse high-grade non-Hodgkin's lymphoma; DF: LYMPHOMA LARGE IMMUNOBLASTIC
ID#: D016400

Lymphoma, Large-Cell, Ki-1

Definition: A large-cell, non-Hodgkin's, malignant lymphoma with pleomorphic appearance and reactivity with the monoclonal antibody Ki-1. The lymphoma is most often found in the skin and lymph nodes and expresses the Ki-1 (CD30) antigen (ANTIGENS, CD30) on its surface. It is often mistaken for metastatic carcinoma and malignant histiocytosis.
Annotation: a non-Hodgkin's lymphoma; DF: note short X ref
ID#: D017728

Lymphoma, Low-Grade

Definition: One of the three major prognostic groupings for non-Hodgkin lymphomas as proposed in the Working Formulation of the Non-Hodgkin's Lymphoma Pathologic Classification Project sponsored by the National Cancer Institute (1981). Lymphomas falling within this group have a relatively favorable survival potential.
Annotation: a grade of non-Hodgkin's lymphoma; prefer specific; LYMPHOMA, HIGH-GRADE & LYMPHOMA, INTERMEDIATE-GRADE & their specifics are also available
ID#: D016397

Lymphoma, Lymphoblastic

Definition: A high-grade malignant lymphoma composed of a diffuse, relatively uniform proliferation of cells with round or convoluted nuclei and scanty cytoplasm. The cells are cytologically similar to the lymphoblasts seen in acute lymphocytic leukemia, and in some cases, the disease may evolve into a leukemic phase morphologically indistinguishable from acute T-lymphocytic leukemia (LEUKEMIA, T-CELL, ACUTE). Lymphoblastic lymphoma represents approximately one-third of the cases of non-Hodgkin's lymphomas in children and 5% of the cases in adults. It is more prevalent in males.
Annotation: a diffuse high-grade T-cell lymphoma
ID#: D016401

Lymphoma, Mantle-Cell

Definition: A rare form of non-Hodgkin lymphoma having a usually diffuse pattern with both small and medium lymphocytes and small cleaved cells. It accounts for about 5% of adult non-Hodgkin lymphomas in the United States and Europe. The majority of mantle-cell lymphomas are associated with a t(11;14) translocation resulting in overexpression of the cyclin D1 gene (GENES, BCL-1).
Annotation:
ID#: D020522

Lymphoma, Mixed-Cell

Definition: Malignant lymphoma characterized by the presence of a mixed population of cells, with the smaller cells resembling lymphocytes and the larger ones histiocytes. It usually presents in a nodular (follicular) pattern, but may evolve into a diffuse pattern. (Dorland, 27th ed)
Annotation: a non-Hodgkin's lymphoma; DF: LYMPHOMA MIXED
ID#: D008227

Lymphoma, Mixed-Cell, Diffuse

Definition: A heterogeneous group of intermediate-grade lymphomas of mixed cellular composition. Although they have not been extensively studied, it appears that they are predominantly B-cell diseases.
Annotation: a diffuse intermediate-grade non-Hodgkin's lymphoma; DF: LYMPHOMA MIXED DIFFUSE
ID#: D016405

Lymphoma, Mixed-Cell, Follicular

Definition: A low-grade malignant lymphoma of follicular pattern in which there is no clear preponderance of one cell type (small or large) over another. The large cells, cleaved or noncleaved, are often 2-3 times larger in diameter than normal lymphocytes.
Annotation: a low-grade non-Hodgkin's lymphoma; DF: LYMPHOMA MIXED FOLLIC
ID#: D016407

Lymphoma, Mucosa-Associated Lymphoid Tissue

Definition: Extranodal lymphoma of lymphoid tissue associated with mucosa that is in contact with exogenous antigens. Many of the sites of these lymphomas, such as the stomach, salivary gland, and thyroid, are normally devoid of lymphoid tissue. They acquire MALT tissue as a result of an immunologically mediated disorder.
Annotation: a low-grade B-cell lymphoma; DF: LYMPHOMA MALT
ID#: D018442

Lymphoma, Non-Hodgkin

Definition: Any of a group of malignant tumors of lymphoid tissue that differ from HODGKIN DISEASE, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumors is the absence of giant REED-STERNBERG CELLS, a characteristic of Hodgkin's disease.
Annotation: GEN & unspecified only: prefer specifics
ID#: D008228

Lymphoma, Small Cleaved-Cell, Diffuse

Definition: An intermediate-grade malignant lymphoma in which the neoplastic cells (B-lymphocytes) exhibit variability in size, configuration, and degree of differentiation. The cells are irregular in shape and have distinct nuclei.
Annotation: DF: LYMPHOMA SMALL CLEAVED DIFFUSE
ID#: D016406

Lymphoma, Small Cleaved-Cell, Follicular

Definition: A low-grade malignant lymphoma of predominantly follicular pattern. Follicles are of relatively uniform size and shape and the cells are usually somewhat larger than normal lymphocytes. Nuclei are irregular with prominent indentations and cytoplasm can rarely be identified. Cells exhibiting these characteristics are often called centrocytes.
Annotation: a low-grade non-Hodgkin's lymphoma; DF: LYMPHOMA SMALL CLEAVED FOLLIC
ID#: D016408

Lymphoma, Small Lymphocytic

Definition: A low-grade malignant lymphoma that may, in some cases, be considered histologically identical to chronic lymphocytic leukemia (CLL; LEUKEMIA, LYMPHOCYTIC, CHRONIC). It is diffuse in pattern, representing the neoplastic proliferation of well-differentiated B-lymphocytes. In patients with immunoglobulin gammopathies, the lymphocytes may exhibit plasmacytoid characteristics.
Annotation: a diffuse low-grade non-Hodgkin's lymphoma
ID#: D016409

Lymphoma, Small Noncleaved-Cell

Definition: A high-grade malignant lymphoma that includes both Burkitt tumor (BURKITT LYMPHOMA) and other lymphomas previously designated undifferentiated non-Burkitt type. Nuclei in Burkitt tumor are round to ovoid and uniform in size. The non-Burkitt type exhibits greater nuclear variation and less evidence of cellular maturation with a correspondingly lesser degree of differentiation.
Annotation: a diffuse high-grade non-Hodgkin's lymphoma; DF: LYMPHOMA SMALL NONCLEAVED
ID#: D016402

Lymphoma, Small-Cell

Definition: A B-cell lymphoma presumably representing a tumor of interfollicular B-lymphocytes that may be functional. Those that are secrete identical immunoglobulin molecules.
Annotation: a non-Hodgkin's lymphoma; DF: LYMPHOMA SMALL
ID#: D008226

Lymphoma, T-Cell

Definition: A group of heterogeneous lymphoid tumors representing malignant transformations of T-lymphocytes.
Annotation: a non-Hodgkin's lymphoma; LYMPHOMA, T-CELL, CUTANEOUS & LYMPHOMA, T-CELL, PERIPHERAL are also available
ID#: D016399

Lymphoma, T-Cell, Cutaneous

Definition: A group of lymphomas exhibiting clonal expansion of malignant T-lymphocytes arrested at varying stages of differentiation as well as malignant infiltration of the skin. MYCOSIS FUNGOIDES and SEZARY SYNDROME are the best characterized of these disorders.
Annotation: a non-Hodgkin's lymphoma; coord IM with SKIN NEOPLASMS (IM)
ID#: D016410

Lymphoma, T-Cell, Peripheral

Definition: A group of malignant lymphomas thought to derive from peripheral T-lymphocytes in lymph nodes and other nonlymphoid sites. They include a broad spectrum of lymphocyte morphology, but in all instances express T-cell markers admixed with epithelioid histiocytes, plasma cells, and eosinophils. Although markedly similar to large-cell immunoblastic lymphoma (LYMPHOMA, LARGE-CELL, IMMUNOBLASTIC), this group's unique features warrant separate treatment.
Annotation: a non-Hodgkin's lymphoma
ID#: D016411

Lymphoma, Undifferentiated

Definition: A form of lymphoma in which relatively large stem cells with large nuclei, pale, scanty cytoplasm, and indistinct borders are predominant. The cells are undifferentiated, i.e., show no morphologic evidence of maturation toward lymphocytes or histiocytes.
Annotation: a non-Hodgkin's lymphoma; DF: LYMPHOMA UNDIFFER
ID#: D008229

Lymphomatoid Granulomatosis

Definition: An angiocentric and angiodestructive lymphoreticular proliferative disorder primarily involving the lungs. Histologically it simulates malignant lymphoma and in some cases may progress to lymphoma.
Annotation: if non-neopl, coord IM with precoord organ/dis term (IM); if neopl, coord IM with precoord organ/neopl term (IM)
ID#: D008230

Lymphomatoid Papulosis

Definition: Clinically benign, histologically malignant, recurrent cutaneous eruption characterized by an infiltration of large atypical cells surrounded by inflammatory cells. The atypical cells resemble Reed-Sternberg cells of Hodgkin's disease or the malignant cells of cutaneous T-cell lymphoma. In some cases, lymphomatoid papulosis progresses to lymphomatous conditions including mycosis fungoides, Hodgkin's disease, cutaneous T-cell lymphoma, or Ki-1 lymphoma.
Annotation: a precancerous form of pityriasis lichenoides
ID#: D017731

Lymphopenia

Definition: Reduction in the number of lymphocytes.
Annotation:
ID#: D008231

Lymphoproliferative Disorders

Definition: Disorders characterized by proliferation of lymphoid tissue, general or unspecified.
Annotation: GEN or unspecified: prefer specifics
ID#: D008232

Lysosomal Storage Diseases

Definition: Inborn errors of metabolism characterized by defects in specific lysosomal hydrolases and resulting in intracellular accumulation of unmetabolized substrates.
Annotation: an inborn error of metab; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES
ID#: D016464

Lysosomal Storage Diseases, Nervous System

Definition: A group of enzymatic disorders affecting the nervous system and to a variable degree the skeletal system, lymphoreticular system, and other organs. The conditions are marked by an abnormal accumulation of catabolic material within lysosomes.
Annotation: GEN: prefer specifics
ID#: D020140