11. Progressive Multifocal Leukoencephalopathy (PML) -
Gross
PML is caused by a papovavirus which infects the oligodendroglia
directly, causing necrosis. Because the oligodendroglia produce
myelin, demyelination occurs in the infected areas, noted in the
gross photograph to the left. The characteristic feature of PML
histologically, seen on the right, is infection of the
oligodendroglial nuclei, resulting in a glassy, smudged appearance of
the nuclear chromatin. Is PML a disease of the immunocompetent or
immunosuppressed population; what is the approximate incidence of the
disease in AIDS patients?
Answer
