抄録
This report deals with our recent observations on 3 cases of atypical acute leukemia difficult to differentiate from aplastic anemia. They were all males, over 60 years old and had lack of definite signs of acute leukemia in their clinical pictures. Onset was insidious, clinical course was mild and prolonged, and physical examinations were unremarkable except for pallor.
Examinations of the blood showed marked pancytopenia with few or no immature cells. Aspirated bone marrow specimens were markedly hypocellular with an infiltration of a small number of blast cells which were characterized by bizzare shape, negative peroxidase reaction and prominent nucleoli and were barely identifiable as myeloblast by the phase contrast microscopical findings.
Chromosomal analysis of cultured peripheral leukocytes disclosed many aneuploid cells including few of 21-Trisomy in 2 cases.
Anemia remained refractory to various therapies, but blood transfusions and administration of prednisolone made the patients' general condition improved.
One case died of unknown cause suddenly after blood transfusion. The principal anatomical findings of this case were bone marrow hypoplasia and mild infiltrations of immature cells in the bone marrow, lymphnodes, spleen and liver.
It is widely known that the clinical picture and course of malignant tumors in aged persons are somewhat different from those in younger people. On this aspect, characteristics of acute leukemia in advanced age group are discussed mainly in association with changes in the immunobiologic capabilities and in the functions of endocrine organs.
