Primary pulmonary cryptococcosis: evaluation of CT characteristics in 26 immunocompetent Chinese patients

Background: Discrepancies still exist in the diagnosis of primary pulmonary cryptococcosis in immunocompetent patients. Purpose: To describe and evaluate radiological manifestations of pulmonary cryptococcosis in immunocompetent patients. Material and Methods: Twenty-six histopathologically confirmed cases of pulmonary cryptococcosis were analyzed for clinical, pathological, and CT characteristics. Necessary statistical tests for differences in CT presentations and correlation analysis between clinical and CT characteristics were performed. Results: The patients' ages ranged from 24 to 79 years, with 20 men and six women. Eighteen patients were symptomatic, with cough as the most common symptom (n = 14, 53.8%). Nodules (n = 21, 80.8%) were the most common CT findings. Eight cases presented with solitary and nine with multiple nodules, while 13 cases presented with irregular and 19 with ill-defined nodules. The halo sign was demonstrated, encompassing nodules in 14 of the 21 patients. Lesions were mainly localized in the lower lobes of the lungs (n = 15, 57.7%) with peripheral distribution (n = 18, 69.2%). Ground-glass opacities (GGOs) were more easily detected in older patients (66.7%, P < 0.01). No significant differences in CT abnormalities were found between male and female patients. Conclusion: Primary pulmonary cryptococcosis in immunocompetent patients exhibits certain CT characteristics. The typical presentation includes multiple nodules with the halo sign scattered in the peripheral field in the lower lobes of the bilateral lungs. This could contribute to diagnosis of the disease entity. However, vigilance should be exercised when facing GGOs, with or without nodules, in older patients.