Objective: To describe the occurrence and characteristics of pleural and peritoneal lymphoma in a large cohort of persons with AIDS in 11 regions in the United States.
Methods: We used AIDS and cancer registries to identify cases of non-Hodgkin lymphoma (NHL) among 304,439 adults with AIDS. NHLs were categorized by site codes into pleural/peritoneal lymphoma and other NHLs. Data on age, sex, HIV exposure category, histology, history of Kaposi sarcoma (KS), CD4 counts, and survival were analyzed.
Results: Fourteen lymphomas were identified (four within the pleura, 10 in the peritoneum) representing 0.13% (95% confidence interval [CI], 0.05-0.20) of 10,510 cases of NHL. Those with pleural/peritoneal lymphoma were similar to those with other NHLs in age (median, 43 years), race (79% white, 7% black, 14% Hispanic), and HIV transmission category (86% homosexual men), but they tended to have a higher prevalence of prior KS (29% vs. 12%; p =.06). More cases of pleural/peritoneal lymphoma had immunoblastic histology than did other NHLs (43% vs. 22%; p =.06). CD4 counts for pleural/peritoneal lymphomas were also higher than for other NHLs (median 203 vs. 65 cells/mm3; p =.05), but post-NHL survival was similar (median 7.1 vs. 5.1 months, respectively; p =.32).
Conclusions: Pleural and peritoneal lymphomas are a rare subtype of AIDS-associated NHL, occurring with less severe immune deficiency than for other NHLs. The increased frequency among persons with prior KS suggests a common etiology, presumably infection with KS-associated herpesvirus, as found in primary effusion lymphoma.