Acute myeloblastic leukemia with t(8;21) following Philadelphia positive acute lymphoblastic leukemia

A patient with Philadelphia positive (Ph'+) acute lymphoblastic leukemia (ALL), in remission for over 4 years, developed an acute myeloblastic leukemia (AML), M2-type. During the second disease, the blast cells displayed a typical t(8;21)(q22;q22) translocation, in the absence of the Ph' chromosome. This is the first observation in the same patient of two leukemias displaying different cell phenotypes and each associated to one of the most characteristic chromosome changes. Cytogenetic characteristics and clinical aspects of the diseases are suggestive for the occurrence of two independent leukemic processes.