| leukoderma colli | A fading of the roseola of secondary syphilis, leaving reticulated depigmented and hyperpigmented areas located chiefly on the sides of the neck. Synonym: leukoderma colli, melanoleukoderma colli. (05 Mar 2000) |
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| leukodermatous | Relating to or resembling leukoderma. (05 Mar 2000) |
| leukodontia | The condition of having white teeth. Origin: Leuko-+ G. Odous, tooth (05 Mar 2000) |
| leukodystrophia | Synonym: leukodystrophy. (05 Mar 2000) |
| leukodystrophia cerebri progressiva | <radiology> Type of dysmyelinating disease, hereditary, peripheral nervous system unaffected in some disorders Specific diseases: adrenoleukodystrophy, metachromatic leukodystrophy, spongy degeneration (Canavan), globoid cell (Krabbe) leukodystrophy, Alexander disease, Pelizaeus-Merzbacher disease, Cockayne syndrome (12 Dec 1998) |
| leukodystrophy | <radiology> Type of dysmyelinating disease, hereditary, peripheral nervous system unaffected in some disorders Specific diseases: adrenoleukodystrophy, metachromatic leukodystrophy, spongy degeneration (Canavan), globoid cell (Krabbe) leukodystrophy, Alexander disease, Pelizaeus-Merzbacher disease, Cockayne syndrome (12 Dec 1998) |
| leukodystrophy with diffuse Rosenthal fibre formation | A metabolic disorder whose onset can be in infancy, adolescence, or adulthood; characterised pathologically by widespread cerebral demyelination with astrocyte and primitive oligodendroglial cell proliferation; refractile Rosenthal fibres result from the degeneration of these proliferating cells; aetiology unknown, but possibly due to a metabolic defect of astrocytes; sex-linked recessive disorder. (05 Mar 2000) |
| leukodystrophy, globoid cell | An inherited metabolic disorder of the nervous system, particularly the white matter. It is characterised histologically by a paucity of myelin and oligodendroglia, severe astrocytic gliosis, and massive infiltration with unique multinucleated globoid cells which are enriched in galactosylceramide. The primary genetic defect is a deficiency of galactosylceramidase. (12 Dec 1998) |
| leukodystrophy, metachromatic | A sphingolipidosis where there is defective desulfation of galactosyl-3-sulfate ceramide due to a defective enzyme cerebroside sulfatase (arylsulfatase a). The result is an accumulation of sulfatide in neural and non-neural tissues which manifests as mental deterioration and severe disturbances of the central nervous system. (12 Dec 1998) |
| leukoedema | A bluish-white opalescence of the buccal mucosa which becomes the normal mucosal colour on stretching the tissue; most commonly observed in blacks and may be considered a normal anatomic variation. (05 Mar 2000) |
| leukoedema, oral | A disorder of the buccal mucosa resembling early leukoplakia, characterised 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 oedema of the spinous or malpighian layer. (12 Dec 1998) |
| leukoencephalitis | Encephalitis restricted to the white matter. (05 Mar 2000) |
| leukoencephalitis, acute haemorrhagic | A rare, fatal postinfection or allergic demyelinating disease of the central nervous system having a fulminating course and occurring mainly in young adults. It is characterised by destruction of white matter to the point of liquefaction; widespread necrosis of blood vessel walls leading to the formation of multiple small haemorrhages in the involved areas and the exudation of fibrin into the surrounding tissue; and cellular infiltration of the necrotic areas. (12 Dec 1998) |
| leukoencephalopathy | White matter changes first described in children with leukaemia, associated with radiation and chemotherapy injury, often associated with methotrexate; pathologically characterised by diffuse reactive astrocytosis with multiple areas of necrotic foci without inflammation. Origin: Leuko-+ G. Enkephalos, brain, + pathos, suffering (05 Mar 2000) |
| leukoencephalopathy, progressive multifocal | Rare demyelinating disease of the central nervous system which develops in immunocompromised patients secondary to lymphoproliferative disease, immunosuppressive therapy, autoimmune disorders, or aids. It is caused by the jc virus, a polyomavirus. (12 Dec 1998) |