Lymphomas involving the pleura: A clinicopathologic study of 34 cases diagnosed by pleural biopsy

Context. - Pleural involvement by lymphoma is relatively common. However, there are very few clinicopathologic studies reported in the literature of lymphomas involving the pleura. Objective. - To characterize the clinicopathologic features of lymphomas involving the pleura. Design. - We reviewed the clinicopathologic features of 34 patients with lymphoma involving the pleura proven by biopsy and classified these neoplasms using the World Health Organization classification. Results. - There were 22 men and 12 women, with an average age of 62 years (range, 22-82 years). Nine (26.5%) patients had pleural involvement as the only site of disease, 22 (64.7%) had other sites of involvement, and 3 (8.8%) had inadequate staging data. Eighteen (56.2%) of 32 patients with adequate clinical data had a history of lymphoma (including 3 patients with pleural involvement as the only disease site). In 29 (85.3%) cases, a specific diagnosis according to the World Health Organization classification could be made: 17 (58.6%) diffuse large B-cell lymphoma, 5 (17.2%) follicular lymphoma (including a case with areas of diffuse large B-cell lymphoma), 2 (6.9%) small lymphocytic lymphomas/chronic lymphocytic leukemia, 2 (6.9%) precursor T-cell lymphoblastic lymphoma/leukemia, 1 (3.4%) mantle cell lymphoma, 1 (3.4%) posttransplant lymphoproliferative disorder, and 1 (3.4%) classical Hodgkin lymphoma. The other 5 cases were B-cell lymphomas that could not be further classified. Cytologic examination of pleural fluid was performed in 15 cases and was positive for lymphoma in 8 (53.3%) cases. Conclusions. - Most patients with lymphoma involving the pleura have simultaneous evidence of systemic involvement. The most frequent type is diffuse large B-cell lymphoma, followed by follicular lymphoma. Cytologic examination can have negative results in patients with pleural involvement by lymphoma.