Pathologic and immunologic characterization of malignant lymphoma in Taiwan. With special reference to retrovirus-associated adult T-cell lymphoma/leukemia.

One hundred four cases of malignant lymphomas, including 90 cases of non-Hodgkin's lymphoma, 5 cases of histiocytic malignancy, and 9 cases of Hodgkin's disease were analyzed pathologically and immunologically using a panel of monoclonal and conventional antibodies for T-, B-, histiocyte, and Hodgkin's neoplastic cells. Our results revealed a high frequency of T-cell lymphoma (42.3%), a low percentage of follicular lymphoma (10.5%), and Hodgkin's disease (8.7%) in Taiwan. More than half of the malignant lymphomas belonged to the high-risk unfavorable group. Peripheral T-cell lymphomas (33 cases) showed characteristic clinical and histologic features, which can sometimes be confused with Hodgkin's disease. Monoclonal antibodies Leu-M1 and 2H9 were an important aid for their differential diagnosis. Five of the 33 peripheral T-cell lymphomas were positive for antibody to adult T-cell lymphoma/leukemia (ATL) virus associated antigen (ATLA). Four patients were from the northeast coast of Taiwan, I-Lan county. Five (4.8%) were diagnosed as true histiocytic malignancies, including two true histiocytic lymphoma and three malignant histiocytosis. Two cases each of large cell lymphoma and immunoblastic lymphoma showed no identifiable marker expression. The distribution of lymphoproliferative disorders in Taiwan is similar to that in Japan but much different from western countries.