[Morphological studies on eosinophils in leukemia].

We investigated morphological changes on eosinophils in two cases each of M2, M4, MDS, and two other cases which showed eosinophilia of more than 5% in bone marrow. Several abnormalities were observed in eosinophils in cases of leukemia. The findings under light microscope frequently revealed granular abnormalities in acute leukemia and nuclear abnormalities in MDS. In acute leukemia, eosinophils were barely detectable in the peripheral blood cells and immature eosinophils increased in the bone marrow. Some cases of acute leukemia showed crystalloid abnormalities in morphology and an increase of eosinophils lacking crystalloid. There was a tendency toward larger-sized granules in cases of M2 and smaller-sized granules in cases of M4. We think that these eosinophils tumorous. It is necessary to accumulate date on more cases, but it seems that, to some extent, there are uniform abnormalities associated with each of the different forms of leukemia.