高令者白血病に関する研究 第1編 高令者低形成型白血病(Hypoplastic Leukemia)に関する臨床的検討

Hypoplastic leukemia has been found frequently in the aged, but its clinical characteristics in relation to age are still obscure. In the present study, clinical and hematological findings from 17 elderly hypoplastic acute myelocytic leukemia (AML) patients were compared with those from 25 elderly typical AML patients. In hypoplastic AML in the old, fever, bleeding tendency, splenomegaly and lymphadenopathy tended to be less frequent. Leukocytopenia, a low percentage of leukemic cells, and lymphocytosis and monocytosis in the peripheral blood seemed to be characteristic of hypoplastic AML. Erythroid hyperplasia with maturation arrest and an increase of type III sideroblasts in the bone marrow were also recognized in hypoplastic cases. In cases without systemic chemotherapy, the median survival from the presumptive onset of leukemia were 12.0 months in hypoplastic patients and 2.5 months in typical patients. In cases with systemic chemotherapy, the median survival of hypoplastic patients was 8.0 months and that of typical patients, 6.5 months. These findings suggest that there is a close relationship between hypoplastic AML in the old and smoldering acute leukemia. On the basis of the present results, hypoplastic AML in the old is thought to be different from typical AML in the old not only clinically and hematologically but also in the response to chemotherapy. The stratification of the hypoplasia in the bone marrow should be examined in order to establish the optimal chemotherapeutic regimen for acute leukemia in the old.