Kaposi's sarcoma involving the lung in patients with the acquired immunodeficiency syndrome.

To determine the distinguishing features of pulmonary Kaposi's sarcoma (KS) in patients with the acquired immunodeficiency syndrome (AIDS), we compared three groups of patients, 16 with endobronchial KS, 15 with endobronchial KS and an opportunistic lung infection, and 40 with Pneumocystis carinii pneumonia (PCP) without concomitant pulmonary KS. The majority of pulmonary KS patients had extensive cutaneous disease at the time of pulmonary diagnosis, and the diagnosis of pulmonary KS was easily established by the characteristic appearance of the endobronchial lesions. Dyspnea, fever, and cough were common presenting symptoms, but occurred more commonly in association with accompanying opportunistic infection. Diffuse interstitial infiltrates were observed in most patients in both groups, but the findings of nodular parenchymal densities or pleural effusion were more commonly observed in patients with pulmonary KS than in those with PCP alone. Pulmonary uptake of gallium-67 citrate or a diffusing capacity less than 80% were unusual in patients with pulmonary KS alone, but common in those with accompanying opportunistic infection or with PCP alone. Median survival in patients with pulmonary KS was only 2 months, and most patients had complicating opportunistic infections at the time of death. Pulmonary KS is generally a late and often preterminal manifestation of AIDS. Chest radiographs, gallium lung scans, and pulmonary function testing may provide diagnostic information that is helpful in distinguishing pulmonary KS from opportunistic lung infections.