A 14-year-old boy admitted to the hospital with dyspnea, was found to have leukocytosis (WBC 90,800/μl) without anemia (Hb 14.5 g/dl) and was diagnosed to have acute myelomonocytic leukemia (AMMoL) based on the FAB M4 morphology of leukemic blasts in blood and bone marrow, associated with chromosomal aberration of t (10; 11). Shortly after daunomycin was given for induction treatment, the patient developed chest pain and chest film revealed infiltration shadows in the left upper and lower lobes, which lasted for four months, unresponsive to intensive antibiotic administration including anti-tuberculous agents. Complete remission of the leukemia was attained in two months, however one year later a relapse occurred. Subsequently, the patient died of congestive heart failure.
Autopsy findings revealed mural thrombi in the right atrium and ventricle, pulmonary thromboembolism, and pulmonary infarction. Retrospectively, it was concluded that the patient already had a pulmonary thrombus at the onset of leukemia, and developed pulmonary infarction soon after treatment for leukemia. The patient developed into complete occlusion of the left pulmonary artery at the time of relapse.
Pulmonary thromboembolism occurs rarely, but should be considered for tachypnea and dyspnea in non-lymphocytic leukemia patients with remarkable increase of WBC.
