[Postoperative pulmonary leukostasis responsible for fatal respiratory distress]

A case is reported of a 78-year-old woman with a history of chronic leukemia and who developed after emergency appendicectomy a fatal respiratory distress syndrome related to pulmonary leukostasis. Clinically, the patient had fever, dyspnea and severe hypoxaemia. Chest x-ray showed diffuse pulmonary infiltrates. The patient died from progressive respiratory failure despite ventilatory support. Post mortem lung biopsies were taken for pathologic examination. They showed thrombi composed of leukaemic blast cells which obstructed and distended the lumens of pulmonary arterioles and capillaries. The respiratory distress is attributed to pulmonary leukostasis. Toxic substances released from the leukostatic leukaemic cell or local hypoxia due to vascular occlusion produce this endothelial cell and basement membrane damage. An infectious origin or endogenous pyrogen substances released from leukaemic monocytes may explain the fever. The frequent occurrence of pulmonary leukostasis in patients with leukocyte count greater than 100,000/mm3 point out the need for prevention or therapy of pulmonary leukostasis in these high-risk patients. They need chemotherapy and, if rapid reduction is not observed, leukopheresis which may favourably influence the outcome of patients.