Occult fifth gland intrathyroid parathyroid adenoma identified by gamma probe

We report the case of a 54-year-old woman undergoing radioguided parathyroidectomy in whom four normal glands were identified on cervical exploration. The gamma probe was instrumental in guiding us to the adenoma in a fifth gland that was not visible and was localized to the parenchyma of the left lobe of the thyroid gland. Many surgeons do not advocate use of the gamma probe in minimally invasive parathyroidectomy and rely solely on focused exploration on the basis of a preoperative sestamibi scan and intraoperative rapid parathyroid hormone assays. This case, however, illustrates the utility of the gamma probe in parathyroid adenoma localization.