Acquisition of Philadelphia chromosome with bcr rearrangement concomitant with transformation of refractory anemia with excess of blasts with 8 trisomy into acute myelogenous leukemia

A case of Philadelphia (Ph1) chromosome positive acute myelogeneous leukemia (AML) following a refractory anemia with excess of blasts (RAEB) with 8 trisomy is reported. The 80-year-old man developed pancytopenia during the course of follow-up after the surgical operation of the carcinoma of the sigmoid colon and the rectum for which no irradiation therapy nor chemotherapy had been applied. The diagnosis of RAEB was made according to the diagnostic criteria proposed by FAB co-operative group. Chromosomal analysis revealed 8 trisomy in 54% of the metaphases of bone marrow cells. The remainders showed normal karyotype without Ph1 chromosome. He was on androgenic steroid and activated Vitamin D3 without significant changes in the clinical and the hematological features until 3 months later when many atypical blasts appeared in the peripheral blood. The diagnosis of AML (M2) was made. Chromosomal analysis revealed Ph1 chromosome with the typical 9;22 translocation in 100% of the examined cells. 8 trisomy was not detected any more. Southern blot analysis using bcr probe showed bcr rearrangement. He was treated with a small doses of Ara-C. There was some reduction in the number of blasts in the peripheral blood. However, he died of septicemia 2 months later. The present case indicates that Ph1 positive acute leukemia with bcr rearrangement is not necessarily considered as a blastic transformation of chronic myelogeneous leukemia and such a cytogenic abnormality can appear in a leukemic transformation of myelodysplastic syndrome.