Abstract
Preoperative localization evaluation is important in surgery for parathyroid tumors; however, accurate evaluation can sometimes be challenging. We report here a case in which pde-neo® was useful in localizing a parathyroid tumor in the thyroid gland. The patient was a woman in her 70s who presented with hypercalcemia and suspected primary hyperparathyroidism. Blood tests showed serum intact parathyroid hormone （PTH） of 183.5pg/mL and calcium of 11.3mg/dL. Ultrasonography and computed tomography scan detected a 7mm-sized mass on the lateral side of the right lobe of the thyroid gland. 99m Tc-MIBI scintigraphy showed residual accumulation on the right side of the neck in the late phase. From these test results, we concluded that the patient had primary hyperparathyroidism caused by the right parathyroid tumor, and subsequently the tumor was resected. Frozen section diagnosis revealed that the mass was suspected to be a schwannoma instead of a parathyroid tumor. Parathyroid tumor could not be detected around the perithyroid area. According to the findings of 99m Tc-MIBI scintigraphy, the right lobe of the thyroid gland was resected in consideration of the possibility of its intra-thyroidal location. Grossly, no parathyroid tumor could be identified in the right lobe of the thyroid gland; however, a luminescent area was observed on the back surface of the thyroid gland by pde-neo®. Permanent histopathological examination confirmed a parathyroid adenoma consistent with the luminescent area. Postoperatively, the level of serum intact PTH and calcium was improved. In this case, preoperative localization evaluation was incorrectly assessed because the parathyroid adenoma was located in the thyroid gland and also coexisted with a schwannoma. However, pde-neo® enabled detection of the location of the parathyroid adenoma intraoperatively.
