The Parathyroid Puzzle: Mapping Adenomas Over Four Years

Abstract

Background: Primary hyperparathyroidism (PHPT) is most commonly caused by a solitary parathyroid adenoma. While preoperative imaging has enabled focused parathyroidectomy, intraoperative decision-making in cases of inconclusive localization still relies heavily on understanding the typical anatomical distribution of adenomas.

Objective: To analyze the anatomical distribution of solitary parathyroid adenomas over a four-year period and identify the most common site.

Methods: This retrospective observational study reviewed 261 patients who underwent parathyroidectomy for PHPT between January 2021 and April 2025 at the Endocrine and Breast Division, Department of General Surgery, SKIMS. Patients with a single adenoma confirmed on imaging and histopathology were included. The location of each adenoma was recorded based on operative findings.

Results: Of the 261 patients (183 females, 78 males; mean age: 32 years), the right inferior parathyroid gland was the most common site of adenoma (45.6%), followed by the left inferior gland (42.1%). Superior gland adenomas were less frequent (left: 5.7%, right: 5.0%). Ectopic adenomas were identified in 1.6% of cases.

Conclusion: The inferior parathyroid glands—particularly the right—are the most frequent sites of solitary adenomas. In cases with inconclusive imaging, initial surgical exploration should focus on the inferior glands. These findings support a strategic approach to focused parathyroidectomy and may help reduce operative time and morbidity.