Several marker analyses of T-lymphoma cells in eight Japanese adults

Lymphoma cells in eight adult Japanese patients with no evidence of overt leukemia throughout their clinical course were demonstrated to be of T-cell nature by combining studies of various immunologic cell surface markers and cytochemistry. The histologic diagnosis of these patients was diffuse histiocytic lymphoma in four patients, poorly differentiated lymphocytic lymphoma in two patients and mixed histiocytic and lymphocytic lymphoma in two patients, according to Rappaport's classification. In seven of the eight patients, the malignant appearance and the large number of E-rosetting cells readily led to the diagnosis of T-cell lymphoma. Human Ia-like antigens were unexpectedly detected on the malignant T cells in seven of the eight patients. TdT activity was elevated in two of the four patients tested. Acid phosphatase activity was always observed in the neoplastic T-cells, and this activity was tartrate resistant. Focal activity of acid alpha-naphthyl acetate esterase was detected in the malignant cells with somewhat mature appearances, but large immature cells had no or weak dispersed activity. Except for E-rosetting ability, malignant T-cells showed such variable properties that multiple marker analyses seem to be necessary in the diagnosis and the prediction of prognosis of these disorders. Frequent occurrence of T-cell malignancy in Japan was also discussed.