[Biclonal co-existence of t(15;17) and t(9;22) chromosomal abnormalities in acute promyelocytic leukemia].

A 50-year-old male was admitted to our hospital with pancytopenia. Peripheral blood examination showed pancytopenia (WBC 450/µl, Hb 7.3 g/dl, Plt 3,000/µl) and elevated FDP. Bone marrow examination demonstrated 38% blasts, 20% promyelocytes and Faggot cells. Cytogenetic analysis demonstrated the following: 46, XY, t(15;17)(q22;q12)[9]/46, XY, del(6)(q?), t(9;22)(q34;q11.2)[1]/46, XY[10]. PML/RARA and minor BCR/ABL were also detected by quantitative reverse transcription polymerase chain reaction of bone marrow cells (52,000 copies/µgRNA and 650 copies/µgRNA, respectively). The patient was diagnosed with acute promyelocytic leukemia. He was treated with all-trans retinoic acid monotherapy and achieved complete hematological remission 51 days after the initial treatment. Post-induction bone marrow examination demonstrated 46, XY[20] and PML/RARA 240 copies/µgRNA, whereas minor BCR/ABL was not detected. The patient's initial cytogenetic analysis suggested the presence of two distinct clones with t(15;17) and t(9;22), which to our knowledge have not previously been reported.