SUN-473 Primary Hyperparathyroidism and Papillary Thyroid Carcinoma, Association or Coincidence?

Background: The Parathyroid glands originate from the Pharyngeal pouches, Inferior from the third and superior from the fourth. Rarely these glands migrate to the thyroid gland, isthmus or thymus and become ectopic. Primary Hyperparathyroidism (PHPT) is a common cause of hypercalcemia in ambulatory patients. It is also more frequent in women and increases with age. Its treatment is often surgical removal of the affected parathyroid gland. We present a case of an ectopic parathyroid adenoma hidden within the thyroid lobe, treated by thyroid lobectomy ultimately leading to the diagnosis and management of Papillary thyroid carcinoma. Case report: A 73-Year-old female with DM, HTN, hyperlipidemia, osteoporosis was referred to the Endocrine clinic for a history of fractures to the right upper and lower extremities after trivial falls, She was subsequently evaluated for metabolic bone disease, noted to have a PTH 78 (n=14-64 pg/ml) with a total serum calcium 9.7 (n=8.6-10.4 mg/dl), 25-OH Vit-D 14 (n=30-100 ng/ml), urinary calcium to creatinine ratio 20 (n=10-320 mg/g). The parathyroid scan showed persistent activity in the area of the inferior margin right thyroid lobe, suggesting a parathyroid adenoma. She had a parathyroidectomy and during the procedure, the parathyroid gland was unable to be visualized. Hence the Right inferior thyroid lobe was removed. The pathology also showed papillary thyroid carcinoma and the patient had a total thyroidectomy. Discussion: The relationship between PHPT and Papillary thyroid carcinoma still remains unclear. Our patient demonstrated a rare circumstance, wherein the presence of a parathyroid adenoma within the thyroid gland has led to early diagnosis and timely treatment of papillary thyroid carcinoma. Few authors reported thyroid malignancy as the most prevalent cancer among patients with PHPT as the primary disorder. While others report concurrence as a coincidental pathology. Nevertheless, we emphasize the importance of surveillance for thyroid pathology in patients with PHPT that can provide better overall patient outcomes. References: 1. Vargas-Ortega, G., et al. (2018). “Symptomatic Primary Hyperparathyroidism as a Risk Factor for Differentiated Thyroid Cancer %J Journal of Thyroid Research.” 2018: 6. 2. Miccoli, P., et al. (2006). “Incidental thyroid carcinoma in a large series of consecutive patients operated on for benign thyroid disease.” ANZ J Surg 76(3): 123-126. 3. Bentrem, D. J., et al. (2002). “Is preoperative investigation of the thyroid justified in patients undergoing parathyroidectomy for hyperparathyroidism?” Thyroid 12(12): 1109-1112.