CASE REPORT Philadelphia Chromosome-Positive Chronic Myeloid Leukemia Expressing pi90BC*-AM'

We describe a case of Philadelphia chromosome-positive chronic myeloid leukemia (Ph-positive CML)expressing pl90BCTAfiL. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of bone marrow cells showed a 472-bp band using primers specific for the pl90*c* ABLbut not \)210PCRmABL transcript. Sequencing analysis revealed that the PCR product was derived from the fusion between BCR exon el and ABLexon a2 (ela2). CMLexpressing pl90*c*" ABLis relatively rare. In a review of the literature, it may be grouped into 2 categories; approximately half of the patients exhibited prominent monocytosis and intermediate hematological phenotype between CMLand chronic myelomonocytic leukemia, and the remaining patients showed no monocytosis. (Internal Medicine 41: 1183-1187, 2002)