[Atypical progressive multifocal leukoencephalopathy (PML) in a patient with pulmonary sarcoidosis]. / Leucoencéphalopathie multifocale progressive atypique chez un patient atteint de sarcoïdose médiastinopulmonaire.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of central nervous system due to the JC virus. PML generally occurs in immunocompromised hosts and has a fatal outcome. OBSERVATION: We report a case of an atypical PML in a patient with pulmonary sarcoidosis: MRI showed multifocal and punctate contrast enhancements. The diagnostic was made by brain biopsy. CONCLUSION: The pathophysiology of this association is probably related to the immunodepression induced by sarcoidosis.