Abstract
Primary hyperparathyroidism (pHPT) is caused by a single or multiple parathyroid adenomas in 85% of cases, by parathyroid hyperplasia in 15%, and by parathyroid carcinomas in less than 1%. Due to the embryological development characteristics of parathyroid tissues, ectopic parathyroid adenomas can be found in various locations. Although the incidence of pHPT varies, it is not considered a rare disease. Some unusual locations of ectopic parathyroid adenomas can make it difficult for clinicians and surgeons to detect them. For this reason, it is important to understand embryology thoroughly and to use complementary preoperative imaging methods. The detection and accurate localization of adenomas are important to avoid recurrent surgeries and to increase surgical success. We aimed to contribute to the literature by presenting a case of an adenoma located in the right pyriform sinus.