Autotransplanted parathyroid adenoma as a rare cause of primary hyperparathyroidism: focused literature review.

BACKGROUND/AIM: Primary hyperparathyroidism (PHPT) is usually caused by a parathyroid adenoma. Parathyroid autotransplantation is commonly performed during thyroidectomy when gland perfusion is impaired. However, the development of adenomas in autotransplanted tissue is extremely rare. We present a case of PHPT caused by an adenoma arising from autotransplanted parathyroid tissue, which occurred 30 years after total thyroidectomy.

METHODS

A 60-year-old woman with a history of total thyroidectomy and parathyroid autotransplantation to the sternocleidomastoid muscle presented with hypercalcemia and elevated parathyroid hormone levels. Ultrasonography suggested a small lesion, but sestamibi scintigraphy was negative. Definitive localization was achieved using 4D-CT and targeted ultrasonography.

RESULTS

Minimally invasive parathyroidectomy was performed, and intraoperative PTH level decreased from 318 pg/mL to 70 pg/mL. Histopathology confirmed a parathyroid adenoma originating from autotransplanted tissue. Postoperatively, calcium and PTH levels normalized.

CONCLUSION

Adenoma formation in autotransplanted parathyroid tissue is very rare but may occur even decades after surgery. Clinicians should systematically evaluate previous autotransplantation sites when they are investigating unexplained or recurrent PHPT, even decades after thyroid or parathyroid surgery.