Pulmonary cryptococcosis: CT findings in immunocompetent patients

Purpose: To evaluate retrospectively the computed tomographic (CT) findings in immunocompetent patients with pulmonary cryptococcosis.

Materials and methods: Institutional review board approval was obtained with a waiver of informed consent, and the study complied with requirements of the Health Insurance Portability and Accountability Act. Chest CT scans of 10 immunocompetent patients with clinically proved pulmonary cryptococcosis were retrospectively reviewed by four reviewers in consensus. Criterion for diagnosis of pulmonary cryptococcosis was (a) the histopathologic presence of the organism at lung biopsy or (b) a positive culture of a respiratory specimen or positive serum cryptococcal antigen test with clinical or radiographic evidence of active pulmonary infection. Patients included six women and four men ranging in age from 46 to 73 years (mean, 59 years). Scans were evaluated for nodules, masses, areas of ground-glass attenuation or of hazy increased attenuation, areas of consolidation, areas of cavitation, pleural effusions, linear opacities, septal thickening, lymphadenopathy, extent of parenchymal involvement, and distribution.

Results: The most common CT finding was pulmonary nodules (n = 9). Multiple nodules (n = 7) were more common than solitary nodules (n = 2). Nodules most commonly occupied less than 10% of the pulmonary parenchyma (n = 7), measured less than 10 mm in diameter (n = 7), and had middle and upper lung predominance (n = 6). The majority of the nodules were well defined with smooth margins (n = 7). Multiple nodules were usually bilaterally distributed (n = 5). Masses (n = 2), lymphadenopathy (n = 2), areas of consolidation (n = 2), areas of hazy increased attenuation (n = 1), pleural effusion (n = 1), and areas of cavitation (n = 1) were uncommon.

Conclusion: CT most commonly demonstrated pulmonary nodules in immunocompetent patients with pulmonary cryptococcosis. The nodules were most often multiple, small, well defined, and smoothly marginated with middle and upper lung predominance.