Letter to the Editor Diagnostic Hematology A Case of Therapy-Related Acute Myeloid Leukemia With a Normal Karyotype After Sustained Molecular Complete Remission of Acute Promyelocytic Leukemia

Given that the current therapeutic regimen for acute promyelo-cytic leukemia (APL) includes idarubicin (a topoisomerase II in-hibitor) and methotrexate (an alkylating agent), therapy-related acute myeloid leukemia (t-AML) can develop after APL treat-ment, and several cases have been reported to date [1-13]. Most of these cases involved the development of secondary clonal cy-togenetic abnormalities following successful treatment of APL, and, to our knowledge, only 2 cases involving a normal karyotype at t-AML diagnosis have been reported [5, 12]. We report a rare case of t-AML with a normal karyotype after sustained molecular complete remission of APL. A 58-yr-old man was admitted in January 2010 because of gingival bleeding and thrombocytopenia. His hemogram results were as follows: White blood cell (WBC) count, 11.4×109/L; Hb, 12.3 g/dL; and platelets, at 51×109/L. Prothrombin time (PT