Intrathymic ectopic parathyroid adenoma caused primary hyperparathyroidism with vitamin D deficiency several years after bariatric surgery

Up to 25% of patients with primary hyperparathyroidism have ectopic parathyroid adenoma. A 45‐year‐old formerly obese woman underwent extended thymectomy for a parathyroid adenoma located in hyperplastic thymic tissue, associated with primary hyperparathyroidism and severe vitamin D deficiency, but normal bone mineral density. At nine months follow‐up, all laboratory test results were within normal limits and she presented no symptoms and no recurrence of disease. In this case, autonomous growth of a parathyroid adenoma was reasonably secondary to chronic calcium and vitamin D malabsorption, which often occurs after bariatric surgery for pathologic obesity.