Disseminated cryptococcosis: Detection by F-18FDG PET

Disseminated cryptococcosis occurs in immunocompromised patients and can affect the skin, prostate, and bones apart from the lungs. Cutaneous manifestations are seen in 10%-15% of cases. Other less common forms of cryptococcosis include myocarditis, hepatitis, chorioretinitis, peritonitis, and renal abscesses. There have been reports of detection of pulmonary cryptococcosis on F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET), which may sometimes lead to diagnostic pitfalls. We report here an unusual case of disseminated cryptococcosis in an immunocompromised patient, which was demonstrated on FDG-PET. The initial diagnosis of cryptococcosis had been made by blood culture and skin biopsy. The chest x-ray was normal but CT showed a solitary pulmonary nodule on the left side. There was, however, uncertainty as to whether the latter was benign or malignant. The whole-body PET images showed multiple sites of abnormal FDG uptake in the skin, lymph nodes, spleen, and lungs, the findings of which were confirmed as cryptococcosis by postmortem examination.