RESUMEN
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 diffi cult to distinguish from other myeloproliferative syndrome such as chronic myeloid leukaemia (CML) because of the similarities in their clinical and bone marrow fi ndings. 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 diffi culty in the classifi cation and treatment of the disease.