Juvenile myelomonocytic leukaemia: a case series

Juvenile myelomonocytic leukaemia (JMML), previously known as juvenile chronic myeloid leukaemia (JCML) is a rare, myelodysplastic – myeloproliferative disease typically presenting in early childhood. This disorder is difficult to distinguish from other myeloproliferative syndrome such as chronic myeloid leukaemia (CML) because of the similarities in their clinical and bone marrow findings. However, because of its unique biological characteristics such as absolute monocytosis with dysplasia, absence of Philadelphia chromosome or BCR-ABL fusion protein, hypergammaglobulinaemia and raised fetal haemoglobin level, this disorder does not satisfy the criteria for inclusion in the CML or chronic myelomonocytic leukaemia (CMML) group, as seen in adult patients. We describe a series of three patients with JMML, who had almost similar clinical and laboratory fi ndings, and discuss the difficulty in the classification and treatment of the disease.