A rare case of supernumerary and ectopic parathyroid adenoma in the parotid gland: diagnostic and surgical challenges.

INTRODUCTION: Primary hyperparathyroidism (PHPT) is a prevalent endocrine disorder characterized by elevated parathyroid hormone (PTH) levels and hypercalcemia, most commonly caused by solitary adenomas. Double adenomas, particularly those arising in ectopic and supernumerary glands, represent a rare diagnostic and surgical challenge. CASE PRESENTATION: We report the case of a 64-year-old woman presenting with symptomatic PHPT. Preoperative imaging demonstrated uptake consistent with two hyperfunctioning parathyroid adenomas, including a rare supernumerary ectopic adenoma in lesion the right parotid region. Definitive diagnosis and surgical planning were guided by 18 F-fluorocholine PET/CT, which proved superior to conventional modalities. DISCUSSION: This case underscores the critical role of advanced imaging techniques in the localization of parathyroid adenomas, particularly in anatomically atypical sites. The combination of functional and anatomical imaging with 18 F-fluorocholine PET/CT enabled accurate detection of both lesions and informed a multidisciplinary surgical approach. CONCLUSION: Integration of 18 F-fluorocholine PET/CT into the diagnostic workflow enhances the precision of parathyroid adenoma localization, especially in rare ectopic presentations. This contributes to tailored surgical strategies and improved patient outcomes. Histopathological examination confirmed two distinct adenomas, including one embedded in the parotid gland, supporting the diagnosis of a supernumerary ectopic parathyroid adenoma.