Pneumocystis carinii peritonitis. Antemortem confirmation of disseminated pneumocystosis by cytologic examination of body fluids.

Histologic confirmation of extrapulmonary Pneumocystis carinii infection in the acquired immunodeficiency syndrome has usually required organ biopsy when the diagnosis was made antemortem. Three cases of Pneumocystis peritonitis were studied in which confirmation of extrapulmonary dissemination was achieved by cytologic examination of ascitic fluid. Patients presented with characteristic choroidal lesions, transudative ascites, profound hypoalbuminemia, and hepatic dysfunction. Cytologic examination of ascitic fluid confirmed extrapulmonary dissemination of pneumocystis. All three patients died despite a minimum of 2 weeks of standard therapy. Cytologic examination of body fluids to confirm dissemination of Pneumocystis may obviate the need for organ biopsy. Disseminated pneumocystosis should be included in the differential diagnosis of ascites or peritonitis in a patient at risk for human immunodeficiency virus--associated opportunistic infections. The presence of transudative ascites may be characteristic of this syndrome.