Philadelphia chromosome positive chronic myelogenous leukemia developing in a patient with acute lymphoblastic leukemia.

A patient with acute lymphoblastic leukemia (ALL) in remission for over five years and with no systemic chemotherapy for over two years developed a peripheral blood and bone marrow granulocytosis. While in remission from the ALL, cytogenetic studies revealed a normal karyotype. With the development of peripheral and marrow granulocytosis, repeat cytogenetic preparations demonstrated the presence of the Philadelphia chromosome. The long interval between the onset of ALL and GML, as well as the normal karyotype during remission from the ALL, causes us to favor the hypothesis that two separate diseases are present.