[Progressive multifocal leukoencephalopathy and pulmonary sarcoidosis].

An association of progressive multifocal leukoencephalopathy (PML) and sarcoidosis in a 47 year-old-woman is reported. This is the third case in which PML has been diagnosed by PCR. Clinical, biological and radiological features were in agreement with previous findings in immunologically suppressed patients. JC virus should be systematically detected by PCR in blood and cerebrospinal fluid (CSF) in patients with sarcoidosis presenting neurological and radiological PML manifestations.