Cerebellar progressive multifocal leukoencephalopathy associated with pulmonary sarcoidosis.

Progressive multifocal leukoencephalopathy can complicate the course of a patient with sarcoidosis. Here we present a rare case of a 35-year-old patient with pulmonary sarcoidosis whose course was complicated by progressive multifocal leukoencephalopathy involving the cerebellum. Neuroimaging and cerebrospinal fluid PCR played a crucial role in the diagnosis.