Pulmonary hypertension in a child with juvenile myelomonocytic leukemia secondary to pulmonary leukemic cell infiltration.

A 4-year-old girl with juvenile myelomonocytic leukemia presented to the emergency room with dyspnea. Echocardiography was performed due to cardiomegaly and prominent main pulmonary artery on a chest X-ray film. On echocardiography the right ventricular pressure calculated from the velocity of tricuspid regurgitation jet was 55 mmHg with no pulmonary stenosis. Despite treatment for pulmonary hypertension and provision of respiratory support, the patient died. A postmortem lung biopsy specimen showed infiltration by tumor cells, which suggested that the pulmonary hypertension had been caused by leukemic infiltration. In conclusion, the findings suggest that leukemic infiltration into the lungs may occur in children with juvenile myelomonocytic leukemia. It should be recognized as a potentially treatable cause of pulmonary hypertension in patients with juvenile myelomonocytic leukemia.