Dicentric Translocation (9;12) Presenting as Refractory Philadelphia Chromosome-Positive Acute B-Cell Lymphoblastic Leukemia

A 66-year-old Caucasian woman presented with a Philadelphia chromosome positive common B-cell acute lymphoblastic leukemia and a dic(9;12) involving the der(9)t(9;22), a rearrangement so far not observed in acute lymphoblastic leukemia. The patient was treated for the acute lymphoblastic leukemia, but showed refractory disease and died 6 months after initial diagnosis. This case suggests that, in the combination of t(9;22) and dic(9;12), the known poor prognostic feature of t(9;22) in acute lymphoblastic leukemia may outweigh the favorable outcome reported in patients with dic(9;12).