Ipsilateral Double Parathyroid Adenomas Causing Primary Hyperparathyroidism: A Rare Case.

Double parathyroid adenomas represent an uncommon but well-recognized subset of primary hyperparathyroidism. Awareness of this possibility is essential, as failure to identify multigland involvement preoperatively may result in intraoperative uncertainty, incomplete resection, and persistent disease. Despite advances in localization techniques, the sensitivity of commonly used imaging modalities - including ultrasonography, technetium-99m sestamibi scintigraphy, and four-dimensional computed tomography - remains limited in detecting double adenomas. We present the case of a patient with primary hyperparathyroidism, who had two left-sided parathyroid adenomas identified on preoperative imaging and confirmed intraoperatively. This report aims to highlight ipsilateral double adenoma disease as a rare but clinically significant entity. In addition, we review adjunctive preoperative risk stratification models and intraoperative biochemical monitoring strategies that may improve recognition of multigland disease and reduce the need for extensive bilateral neck exploration.