Pulmonary cryptococcosis: imaging findings in 23 non-AIDS patients

We aimed to review the patterns of lung abnormalities of pulmonary cryptococcosis on CT images, position emission tomography (PET) findings of the disease, and the response of lung abnormalities to the therapies in non-AIDS patients.

We evaluated the initial CT (n = 23) and 18F-fluorodeoxyglucose (FDG) PET (n = 10), and follow-up (n = 23) imaging findings of pulmonary cryptococcosis in 23 non-AIDS patients. Lung lesions were classified into five patterns at CT: single nodular, multiple clustered nodular, multiple scattered nodular, mass-like, and bronchopneumonic patterns. The CT pattern analyses, PET findings, and therapeutic responses were recorded.

A clustered nodular pattern was the most prevalent and was observed in 10 (43%) patients. This pattern was followed by solitary pulmonary nodular (n = 4, 17%), scattered nodular (n = 3, 13%), bronchopneumonic (n = 2, 9%), and single mass (n = 1, 4%) patterns. On PET scans, six (60%) of 10 patients showed higher FDG uptake and four (40%) demonstrated lower FDG uptake than the mediastinal blood pool. With specific treatment of the disease, a complete clearance of lung abnormalities was noted in 15 patients, whereas a partial response was noted in seven patients. In one patient where treatment was not performed, the disease showed progression.

Pulmonary cryptococcosis most commonly appears as clustered nodules and is a slowly progressive and slowly resolving pulmonary infection. In two-thirds of patients, lung lesions show high FDG uptake, thus simulating a possible malignant condition.