Renal cortical nephrocalcinosis: a manifestation of extrapulmonary Pneumocystis carinii infection in the acquired immunodeficiency syndrome.

A 38-year-old man with acquired immunodeficiency syndrome (AIDS) demonstrated atypical nephrocalcinosis on abdominal x-ray. Computed tomography (CT) scanning showed the calcifications to be predominantly in a cortical distribution. The patient had evidence of disseminated Pneumocystis carinii infection, and histologically the renal calcifications occurred in areas of renal Pneumocystis infection. Intrarenal infection with Pneumocystis carinii can be added to the causes of nephrocalcinosis. However, the radiologic picture is so unique that it should suggest the diagnosis in the appropriate patient.