Pleural and peritoneal lymphoma among people with AIDS in the United States

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.

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.

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).

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.