The article presents information about the study of morphological features in progressive multifocal leukoencephalopathy caused by polyomavirus infection in HIV-infected individuals. A study of sectional material (the brain) was carried out. After routine proceeding and histological staining, the slides were studied under Olympus BX41 microscope, followed by a morphometric examination. According to neuroimaging methods, the presence of multiple foci in the brain may be caused by the presence of several etiological factors: JCV, BKV, EBV, T. gondii, and C. neoformans, which requires mandatory laboratory confirmation. Morphological changes in the brain in PML caused by JCV and BKV are characterized by areas of demyelinated lesions 2-3 mm in size with a tendency to merge, with significant areas of white matter affected and degenerative changes predominantly in the juxtacortical/subcortical white matter.
