Philadelphia-chromosome-positive, monosomy 7 biphenotypic acute mixed lineage leukemia in adults : a pluripotent stem cell disorder

Two adult patients with acute mixed lineage leukemia (AMLL) having combined Philadelphia chromosome (Ph 1 ) positivity and monosmy 7 are presented. The phenotypes of leukemic blasts from both cases were almost same (early B-lymphoid lineage and myeloid lineage); CD10 + , CD13 + , CD19 + . HLA-DR - , and dual-color analysis showed simultaneous expression of CD10 (CD19) and CD13 antigens in individual blasts (biphenotypic) in both cases. On molecular analysis, the leukemic blasts showed rearrangement in the first intron of the BCR gene with breakpoint just outisde of 3' end of m-BCR-2 (bcr 3) in case 1, and in the M-BCR in case 2