Background: Juvenile myelomonocytic leukemia is a rare hematopoietic stem cell disease in children with features of both myelodysplasia and myeloproliferation. Extramedullary involvement has been reported and pulmonary involvement secondary to leukemic infiltration is an initial manifestation, which may result in acute respiratory failure.
Observation: We present 3 children with juvenile myelomonocytic leukemia and suspected pulmonary leukemic cell infiltration who all also suffered from respiratory insufficiency. The differential diagnosis included asthma and infections.
Conclusions: In each case the patients improved rapidly after initiation of antileukemic treatment including 6-mercaptopurine or cytarabine.