The accuracy of high resolution computed tomography (HRCT) in the diagnosis of pulmonary lesions arising in patients with leukemia, lymphoma, or other hematopoietic proliferative disorders was evaluated in postmortem lung specimens from 35 patients with one of these neoplasms. Lungs were obtained from autopsied patients and prepared in a manner that allowed for direct pathologic-radiologic correlation. Eighty-eight pulmonary lesions with one of five radiographic patterns were identified in these 35 lungs. The gross, histologic, and radiographic changes were examined and the radiologic and pathologic diagnoses for each lesion were compared. A diffuse alveolar pattern on HRCT was primarily the result of pneumonia or intraalveolar hemorrhage, while irregular focal densities were produced by foci of hemorrhage, infarcts, lymphoma, and fungal infections. HRCT of the lung from a patient with pulmonary histiocytosis X showed a wedge-shaped subpleural density in association with a "crab-like" interstitial pattern, which was histologically shown to be an infarct with interstitial enlargement by infiltration of histiocytosis X. Air bronchograms were seen in two settings. In patients with necrotizing pneumonia, air bronchograms were associated with bronchiectasis. In contrast, air bronchograms seen in a patient with a bronchocentric lymphoproliferative disorder showed a pattern of bronchial constriction. These results suggest that HRCT may play an important role in the evaluation of pulmonary lesions in patients with leukemia, lymphoma, or other hematopoietic malignancies.