Endocrine Abstracts

Introduction: Primary hyperparathyroidism (PHPT) involves excessive secretion of parathyroid hormone (PTH), leading to elevated serum calcium levels. Ectopic parathyroid adenomas, constituting 10-22% of cases, arise due to abnormal embryonic migration and can be located from the mandible to the pericardium. This complicates their localization and diagnosis. Parathyroidectomy, with a success rate over 90%, remains the treatment of choice. This case report discusses the diagnostic challenges and management in a PHPT patient with an ectopic parathyroid adenoma.

Clinical Case: A 61-year-old male was referred to our endocrinology service in March 2017 for persistent, asymptomatic hypercalcemia, with levels between 2.76 and 2.86 mmol/l and elevated PTH levels. The patient, on active surveillance for prostate cancer, had no significant past medical or family history. Ultrasound kidneys showed no stones, and a DEXA scan revealed normal bone density. He was advised to increase fluid intake, avoid calcium supplements, and monitor calcium levels biannually with his GP. By July 2022, his calcium levels had risen to 3.06 mmol/l, necessitating further investigation. A SESTAMIBI scan indicated increased uptake in the right posteroinferior thyroid lobe, but a parathyroid ultrasound did not confirm an adenoma. The SESTAMIBI uptake was located inferiorly for neck ultrasound localization, suggesting a retrotracheal position. Consequently, a 4DCT scan was performed, revealing an 11x20x32 mm lesion in the posterior mediastinum, lateral to the oesophagus, consistent with an ectopic parathyroid adenoma. The patient underwent a successful parathyroidectomy with postoperative normalization of calcium levels.

Conclusion: This case illustrates the necessity of a systematic approach in managing PHPT with atypical presentations like ectopic adenomas. Effective diagnosis and management involve a multidisciplinary team (endocrinologists, radiologists, and surgeons). The successful surgical intervention not only normalized the patient’s calcium levels but also demonstrated the effectiveness of targeted surgery in managing complex hypercalcemia cases due to ectopic parathyroid adenomas.