Coexistence of translocation(1,19) and the Philadelphia chromosome in a child's first presentation of chronic myeloid leukemia in blast crisis treated with dasatinib.

Chronic myelogenous leukemia (CML) constitutes less than 5% of childhood leukemias. The authors describe a rare case of a 14-year-old boy who presented with CML in blast crisis. Unique to this patient was the evidence of both breakpoint cluster region-c-abl oncogene 1 (BCR-ABL1) fusions as well as an additional unbalanced t(1;19) translocation. This combination has not previously been reported in the same patient. Initial treatment with dasatinib achieved a complete cytogenetic response within 2 months of therapy. This case highlights the heterogeneous presentation of CML in children and rationale for use of dasatinib as a first-line agent for patients with blast crisis.