A case of acute lymphoblastic leukemia with additional chromosomes X and 5 associated with a Philadelphia chromosome in the bone marrow.

We report herein a very rare case of acute lymphoblastic leukemia having a chromosomal constitution of 48,XY,+X,+5,t(9;22)(q34;q11) in the bone marrow. A patient with additional chromosomes X and 5 with a Philadelphia chromosome has not been reported previously. However, no abnormal karyotype was obtained from the lymphocytes in our patient, and he did not have the characteristics of Klinefelter syndrome. He achieved a complete remission with IDA-FLAG and dasatinib therapy. The mechanism of trisomy 5 or any other chromosomal aneuploidy in the pathogenesis of leukemogenesis remains unclear. Further studies involving the genes affected by this karyotype and their products may lead to strategies to further increase the understanding of drug-resistant acute lymphoblastic leukemia and may represent the next frontier in the targeted therapy of those patients.