Childhood chronic myeloid leukemia with monocytosis

We report two cases of chronic myeloid leukemia (CML) in childhood presenting with monocytosis. History, physical examination and laboratory findings were in favor of juvenile myelomonocytic leukemia in both the cases, but reverse transcriptase polymerase chain reaction (RT-PCR) detected b2a2 and b3a2 transcript of p210 bcr-abl protein characteristic of major BCR breakpoint. Presence of monocytosis in early childhood suggests a viral infection or JMML but a possibility of CML with monocytosis needs to be considered.