Listeria rhomboencephalitis in a patient on a tumor necrosis factor α inhibitor (etanercept).

We describe a case of an 87-year-old woman with rheumatoid arthritis on etanercept who developed subacute encephalopathy. Magnetic resonance imaging and blood cultures led to the diagnosis of Listeria monocytogenes rhomboencephalitis, which proved to be fatal. Postmortem examination of the brain revealed abscesses with extensive necrosis. Gram stain showed small gram-positive rods in the necrotic tissue and the wall lining the abscesses. While rhomboencephalitis is a rare entity, and clinical recognition may be hampered by immunosuppression such as in this case, early blood cultures, lumbar puncture, and empiric treatment with ampicillin should be initiated in all patients with suspected rhomboencephalitis if suggested by imaging and by a clinical concern for infection.