Philadelphia positive chronic myeloid leukemia mimicking acute lymphoblastic leukemia in a child

Abstract

Chronic myeloid leukemia (CML) is a rare hematological malignancy in children. The more common acute lymphoblastic leukemia (ALL) needs to be excluded in cases with lymphoid blast crisis phase of childhood CML. A 12-year-male child with generalized lymphadenopathy and hepatosplenomegaly had a crisis phase of presentation instead of the usual chronic phase of onset of disease. Hematological tests and molecular study were performed. Peripheral blood, bone marrow and lymph node fine-needle aspiration cytology smear showed features of CML in blast crisis. Blast cells were myeloperoxidase negative. Philadelphia chromosome with major BCR-ABL fusion product and B-cell lineage immunomarkers indicated CML origin of blasts rather than de novo ALL. Usually myeloid blast crisis is common in CML but the present case had lymphoid blast crisis which is less commonly documented. We report a case of ‘adult form of CML in the juvenile age group with lymphoid blast crisis and extramedullary blast proliferation.’