Patients of chronic myeloid leukemia (CML) eventually transform to blast crisis (BC) after a variable length of chronic phase (CP). With improvement in management protocols, many patients of CML-BC are expected to show remission after initial chemotherapy and a better survival. Hence, it becomes imperative to correctly classify the nature of BC for further course of management.

This study retrospectively analyzed cases of CML-BC, over a period of 5 years, with comprehensive immunophenotyping done on flow cytometry.

Fifteen cases of CML-BC with male-to-female ratio of 3:1 and mean age of 40.2 years were included in the study. Flow cytometry revealed 14 cases of myeloid and one case of lymphoid BC. One case each of megakaryocytic and myelomonocytic lineage were seen among the 14 cases of myeloid BC. Aberrant marker expression was a common occurrence. Myeloperoxidase cytochemical stain had shown positivity only in 3 of the 14 cases of myeloid BC.

Immunophenotyping is necessary for assigning specific lineage to blasts in patients of CML-BC and thus providing clinically useful information regarding the treatment protocols and prognosis of the patient.

Narang V, Sachdeva MUS, Bose P, Varma N, Malhotra P, Varma S. Immunophenotyping in Chronic Myeloid Leukemia Blast Crisis: Looking beyond Morphology. J Postgrad Med Edu Res 2016;50(4):181-184