Pulmonary complications of acute leukemia

The lungs of 50 consecutive autopsied cases of acute leukemia were studied and cultures were obtained from 36. Thirty‐one patients had major pulmonary lesions. Most of these were not recognized antemortem. Infection was the most common pulmonary complication. Pulmonary disease was present in 95% of those cases with abnormal chest x‐rays but 59% of the patients with normal chest x‐rays also had pulmonary pathology. Leukemic involvement was identified microscopically in 64% of the lungs. Peribronchial infiltrates were found most frequently. Patients with high levels of circulating abnormal cells had more severe leukemic involvement of the lung. Pulmonary hemorrhage was found in 54% of the lungs and was severe in 12%. The incidence of pulmonary hemorrhage was higher in patients with severe thrombocytopenia. Thirty‐one major and 29 minor pulmonary infections were found in 40 of the patients. Many of these were unrecognized clinically and the offending organism was seldom isolated antemortem. The most frequently identified pathogens were Pseudomonas sp., Candidia sp., and Aspergillus sp.