A Rare Intraoperative PTH Level Spike Immediately After Parathyroid Resection: A Case of an Additional Adenoma

Primary hyperparathyroidism is a frequent cause of hypercalcemia resulting from one or more parathyroid adenomas. We report the case of a 66-year-old female who underwent parathyroidectomy, during which intraoperative parathyroid hormone (ioPTH) levels spiked tenfold, from 197 pg/mL to 2,209 pg/mL, 10 minutes post-resection. Despite recalibration and re-sampling, ioPTH levels further increased to 3,000 pg/mL at 1 hour, prompting additional exploration and resection of a second adenoma. The patient’s serum calcium levels subsequently returned to normal postoperatively. This case highlights the importance of considering additional parathyroid adenomas in patients with unexpected spikes in ioPTH levels and underscores the need for thorough exploration rather than attributing such rises solely to laboratory error.