Tc-99m-MIBI SPECT/CT imaging to diagnose secondary hyperparathyroidism after parathyroid forearm transplantation.

This article report a 40-year-old male patient who underwent total thyroidectomy and forearm auto-transplantation in another hospital for secondary hyperparathyroidism. After 4 years of follow-up, the level of parathyroid hormone continued to increase, and ultrasound showed nodules in the neck and right forearm, which were considered to be of parathyroid origin. Technetium 99m sestamibi single photon emission computed tomography and computed tomography (Tc-99m-MIBI SPECT/CT) imaging showed increased radioactive uptake in the submuscular soft tissue nodule of the right medial forearm, maximum standardized uptake value (SUVmax) is 0.98, which was identified as transplanted functioning parathyroid tissue. No parathyroid imaging activity was found in the neck. The patient then underwent partial removal of ectopic parathyroid tissue from the right forearm. Pathological examination confirmed parathyroid tissue, and removal was followed by a rapid decline in serum parathyroid hormone levels.