Cytogenetic Studies in Eosinophilic Leukemia

Abstract

The results of cytogenetic studies of 2 patients believed to be examples of eosinophilic leukemia are reported. Although the Ph1 chromosome typical of chronic myelocytic leukemia was not found in these patients, morphological abnormal chromosomes were present in each patient. A very large acrocentric chromosome was seen in 4 metaphases from one patient in the peripheral blood leukocytes culture and in 6 metaphases in the direct bone marrow preparation in the other. There is no evidence that this abnormal chromosome replaced any particular normal chromosome. These findings suggest that eosinophilic leukemia is not a varient of chronic myelocytic leukemia in which eosinophilic proliferation happens to be more prominent, but may be a distinctive malignant myeloprolifera-tive disorder.