Frequency of eosinophilia in adult T‐cell leukemia/lymphoma

Cases of adult T-cell leukemia/lymphoma (ATLL) display several peculiar clinical features, including skin rash, hypercalcemia, and an increase in the absolute neutrophil count. The patients rarely have pronounced eosinophilia. In this study, the eosinophilia observed in lymphoproliferative disorders of 62 patients with ATLL, 27 with T-cell lymphoma (TL), and 19 with B-cell lymphoma (BL) was investigated. The incidence of eosinophilia (⩾ 570/μl) was higher in patients with ATLL than in patients with TL or BL. Thirteen patients with ATLL (21.0%), 3 with TL (11.1%), and 2 with BL (10.5%) had eosinophilia. Of these patients, three with ATLL and one with TL who had a pathologic diagnosis of immunoblastic lymphadenopathy (IBL) showed pronounced eosinophilia up to 10,934/μl. Because the number of eosinophils in the peripheral blood of these patients correlated both with the number of ATLL cells and the degree of lymphadenopathy and because this fluctuated with chemotherapy, it seems likely that the secretion of some lymphokines by the lymphoma cells is responsible for the eosinophilia. Cancer 1992; 69:966–971.