Chronic myelogenous leukemia and acute lymphoblastic leukemia occurring in the course of polycythemia vera

We are reporting an unusual case of a 54-year-old woman with polycythemia vera (PV) who developed Ph chromosome positive chronic myelogenous leukemia (CML) 8 years after the initial diagnosis of PV, and terminating in acute lymphoblastic leukemia (ALL), 11 years after the initial diagnosis. Cytogenetic studies revealed a normal female karyotype at the time of diagnosis of PV and the presence of a Ph chromosome at the time of appearance of CML. Southern blot hybridization revealed a bcr rearrangement in both mononuclear cells and granulocytes. The diagnosis of ALL was established on the basis of morphology, positive TdT staining, and monoclonal antibody studies positive for 12, B4, and J5. This case demonstrates the transition of PV into CML, followed by a blastic transformation into acute lymphocytic leukemia. At termination of her disease there were findings compatible with bi-phenotypic leukemia. These findings would suggest that the disease arose in a primitive multipotential stem cell.