Pleural effusions in patients with AIDS

Objective: To describe the range of pathology causing pleural effusions in HIV infected patients with acute respiratory episodes and to attempt to ide ntify whether any associated radiological abnormalities enabled aetiologica l discrimination. Methods: Prospective study of chest radiographs of 58 consecutive HIV infec ted patients with pleural effusion and their microbiological, cytological, and histopathological diagnoses. Results: A specific diagnosis was made in all cases. Diagnoses were Kaposi' s sarcoma, 19 patients; parapneumonic effusion, 16 patients; tuberculosis, eight patients; Pneumocystis carinii pneumonia, six patients; lymphoma, fou r patients; pulmonary embolus, two patients; and heart failure, aspergillus /leishmaniasis, and Cryptococcus neoformans, one case each. Most effusions (50/ 58) were small. Bilateral effusions were commoner in Kaposi's sarcoma (12/19) and lymphoma (3/4) than in parapneumonic effusion (3/16). Concomita nt interstitial parenchymal shadowing did not aid discrimination. A combina tion of bilateral effusions, focal air space consolidation, intrapulmonary nodules, and/or hilar lymphadenopathy suggests Kaposi's sarcoma. Unilateral effusion with focal air space consolidation suggests parapneumonic effusio n if intrapulmonary nodules are absent: if miliary nodules and/or mediastin al lymphadenopathy are detected, this suggests tuberculosis. Conclusions: A wide variety of infectious and malignant conditions cause pl eural effusions in HIV infected patients, the most common cause in this gro up was Kaposi's sarcoma. The presence of additional radiological abnormalit ies such as focal air space consolidation, intrapulmonary nodules, and medi astinal lymphadenopathy aids aetiological discrimination.