131I Whole-Body Scan Incidental Uptake Due to Spermatocele
A 46-year-old man with papillary thyroid cancer post total thyroidectomy was referred for post radioiodine (131I) whole-body scan. Whole-body images revealed intense 131I uptake in the bed thyroid and a focal abnormal uptake in the testicular area. Subsequent SPECT/CT demonstrated that the focal uptake corresponded to the left epididymis, and the pathology report revealed a spermatocele with no immunohistochemical features for thyroid tissue. Many cases of unexpected radioiodine uptake have been reported, and spermatocele could be counted for another possibility of incidental 131I uptake despite an unclear mechanism.