A 70-year-old man with T-cell deficiency experienced continuous right waist pain and a low degree of fever. Abdominal CT found a large right adrenal mass. FDG PET/CT imaging was acquired to identify the nature of this likely malignant mass and search for potential metastases. The images revealed increased FDG activity in the mass. The patient received right adrenalectomy. Postsurgical pathological and microbial examination demonstrated adrenal cryptococcosis.