CD5-EXPRESSING B-CELL LYMPHOMAS LEUKEMIAS - RELATIVELY HIGH-FREQUENCYOF CD5(+) B-CELL LYMPHOMAS WITH AN OVERALL POOR-PROGNOSIS IN NAGASAKIJAPAN/

To characterize CD5(+) B-cell neoplasms in Japan, where chronic lympho cytic leukemia (CLL) is rare and of different subtypes in comparison w ith Western countries, we collected 58 cases of CD5(+) B-cell lymphoma s/leukemias and analyzed their clinicopathologic features. According t o the French-American-British (FAB) and standard histologic classifica tions, the cases corresponded to small lymphocytic lymphoma (SLL, grou p I; n = 22, consisting of CLL, n = 10, CLL/PL, n = 3, and CLL(mixed), n = 7); intermediate differentiated lymphoma/mantle cell lymphoma (ID L/MCL, group II, n = 18); and others with CDS-positive lymphomas (grou p III, n = 18). The CD5(+) B-cell lymphomas showed morphologic and pro gnostic variability among the three groups. The clinical and immunophe notypic features were remarkably consistent in leukemic disease being seen in 73% of all cases, splenomegaly in 63%, and intense CD19, CD20, surface membrane immunogobulin M (SmlgM) or SmIgM and SmIgD, light-ch ain expression, and no CD10 expression. The median survival time of gr oups I, II, and III was 7.8, 3.3, and 0.8 years, respectively. These f indings suggest that CD5 antigens may serve as valid markers for the p rognosis and clinical features of B-cell lymphomas and that CD5(+) B-c ell lymphomas with an overall poor prognosis occurs at a relatively hi gh frequency in Japan. This also suggests that a combination of immuno phenotypic and morphologic features is of value for characterizing CD5 (+) B-cell neoplasms.