Endocrine Abstracts

Parathyroid carcinoma is a rare (<1-5%) cause of primary hyperparathyroidism (pHPT) marked by excessive parathyroid hormone secretion leading to hypercalcemia. The prevalence rate of parathyroid carcinoma is 0.005% among all malignancies which has a slow and indolent course. A 53 year old male presented with lassitude, constipation, and bone pains which are common but non-specific symptoms. Diagnostic examination showed ionized calcium of 2.16mmol/l, nephrolithiasis, elevated creatinine and shortened QT interval. Intact PTH (iPTH) is elevated at 177.57 pg/ml with normal thyroid function tests. Hypercalcemia was managed with hydration and diuretics. Imaging revealed a hypoechoic mass posterior to the thyroid gland. Sestamibi scan showed increased tracer accumulation almost occupying the entire right lobe. Right inferior parathyroidectomy with right thyroid lobectomy was done wherein biopsy revealed parathyroid carcinoma. Post-operative iPTH showed a significant decline (>50%) from baseline at 39.91 pg/ml indicating complete removal of the abnormal hyperfunctioning parathyroid gland. Succeeding iPTH and serum calcium showed a decreasing trend alongside improving signs and symptoms. Although parathyroid carcinoma is rare, its manifestations as a result of hypercalcemia is common. Given that the best chance for treatment success is with a complete en-bloc resection, early diagnosis is imperative for treatment success and prolonged disease-free survival.