A 69-year-old man with left hemispheric necrotizing mass lesion: Com March 2009 case 2

We report the first case of primary non-Hodgkin lymphoma of the central nervous system in a 69-year-old patient with chronic inflammatory demyelinating polyneuropathy (CIDP) on long-termimmunosuppression. CIDPwas diagnosed 4 years earlier and treated with plasma exchange, corticosteroids, azathioprine andmycophenolate mofetil. The patient developed an organic brain syndrome and cerebralMRIrevealed multiple enhancingT1 lesions in the periventricular parenchyma. A stereotactic biopsy was not diagnostic, but Epstein-Barr virus (EBV) was detected in the cerebrospinal fluid. After a fulminant course of an illness resembling an encephalitis the patient died. Postmortem analysis confirmed the diagnosis of EBVassociated diffuse large B cell lymphoma. This case illustrates the risks of life-threatening infections associated with continuous immunosuppression, and emphasizes the need for an extensive diagnostic work-up in patients who present with signs and symptoms of an unexpected encephalopathy.