An unusual cause of mastoiditis that evolved into multiple ring-enhancing intracerebral lesions in a person with HIV infection.

Acute mastoiditis, an infectious inflammatory process in the temporal bone, is an uncommon complication of otitis media. Here we describe a fatal case of mastoiditis complicated by thrombosis of the sigmoid sinus and intracerebral abscess caused by an unusual pathogen (Nocardia asteroides) in a person with HIV infection. Sulfonamides have remained the first-line agents for the management of Nocardia infections, but mortality remains high in patients with intracerebral infection.