Cytology of pericardial effusions in AIDS patients.

Pericardial effusions in patients with the acquired immunodeficiency syndrome (AIDS) can be due to a variety of causes and are often large enough to be sampled for cytologic examination. Over a period of 46 months, 15 cytologic specimens from 14 patients with AIDS were examined. Thirteen patients were male, one was female; the age range was 26 to 43 years. All male patients were homosexual or intravenous drug abusers, and the female patient was the spouse of an intravenous drug abuser. In general, the cytology specimens were moderately cellular with inflammatory cells seen in all cases. Atypical or reactive mesothelial cells were found in 12 cases (80%), and the atypia in one of these 12 was so marked that carcinoma was suspected; cells suspicious for malignant lymphoma were found in 2 cases (13%); degenerated mesothelial cells were present in one case. No infections were identified in this series. Ten patients (66%) had subsequent pericardial biopsies. Marked cellularity and nuclear pleomorphism in lymphoid cells with an altered nuclear cytoplasmic ratio were the dominant findings in the two suspected lymphoma cases. Both patients had known lymphoma elsewhere; in one, involvement by lymphoma was also found on pericardial biopsy. Mesothelial proliferations showing papillary formations with psammoma bodies were seen in three cases; in one of these, histoplasmosis was later diagnosed by pericardial biopsy. To our knowledge this is the first series to describe cytologically the marked mesothelial atypia seen in pericardial fluid in AIDS patients. We contrast this atypia with that seen in malignant effusions and caution against overinterpretation of pericardial fluids from AIDS patients.