[Case 1] A 44-year-old female was referred to our hospital because of
leukocytosis. The WBC count was 26400/microliters and NAP score 21. As
Ph1 chromosome was detected, she was diagnosed as CML and treated with
busulfan. Because of the rapid decrease of WBC, we stopped
busulfan. Progressive
pancytopenia and an increase of myeloblasts and promyeloblasts in the bone marrow was observed. We started
vincristine and
prednisolone therapy.
Ph1 chromosome was not detectable and southern blot analysis did not show rearranged bands of M-bcr three years after the last
therapy. [Case 2] A 74-year-old female was referred to our hospital by reason of
leukocytosis and
thrombocytosis. The WBC count was 22,500/microliters, the platelet 907,000/microliters, NAP score 53, and
Ph1 chromosome was found. The diagnosis of CML was made, and she was treated with
busulfan. The WBC rapidly fell to 1,900/microliters, when chromosome analysis revealed the presence of Ph1 negative clones (4/20). She was admitted due to
thrombocytopenia and
leukocytosis with the additional chromosome change of i (17q). Her peripheral blood and bone marrow pictures were consistent with
blast crisis, and she died of
cardiac tamponade. These two cases show the heterogeneity of CML patients, and also suggest the possibility that keeping the WBC count low may lead to a decrease of Ph1 positive clones.