Pulmonary Cryptococcosis: CT and Pathologic Findings

PURPOSE: The purpose of this work was to describe the CT and pathologic findings of pulmonary cryptococcosis. METHOD: CT scans of 11 patients (7 immunocompromised, 4 immunocompetent) with proven pulmonary cryptococcosis were analyzed for number, morphologic characteristics, and distribution of parenchymal abnormalities as well for presence of lymphadenopathy and pleural effusion. Pathology of lung specimens obtained by open biopsy or resection (n = 5) and transbronchial biopsy (n = 1) was reviewed by one dedicated pulmonary pathologist. RESULTS: Pulmonary nodules, either solitary or multiple, were the most common CT finding, present in 10 of 11 patients (91%); associated findings included masses (n = 4), CT halo sign (n = 3), and consolidation (n = 2). On histologic examination, focal areas of ground-glass attenuation surrounding or adjacent to nodules were found to represent airspace collections of macrophages and proteinaceous fluid. CONCLUSION: Pulmonary cryptococcosis should be considered in the differential diagnosis of solitary or multiple pulmonary nodules (with or without associated CT halo sign), particularly in immunocompromised patients.