Central nervous system lymphoma associated with mycophenolate mofetil in lupus nephritis

Lymphomas, both within and outside the central nervous system, are uncommon among patients with systemic lupus erythematosus (SLE). We describe a 58-year old Korean woman with SLE who presented with acute headache and confusion in the setting of prednisone and mycophenolate mofetil (MMF) therapy used to treat focal proliferative and membranous lupus nephritis. Three-dimensional brain magnetic resonance imaging (MRI) showed two peripherally ('ring') enhancing lesions within the basal ganglia, bilaterally, with associated mass effect and subfalcine herniation. A brain biopsy revealed an Epstein-Barr virus (EBV)-positive diffuse large B cell lymphoma. This is the first description of CNS lymphoma in a patient treated with MMF for lupus nephritis. While intracerebral lymphoma in the immunocompromised patient with lupus is rare, this disorder should be considered in the differential diagnosis of new-onset neurological symptoms among such patients.