A very rare, slow-growing, clinically serious endocrine tumor that generally develops in mid-adulthood. PRTC presents as a palpable painless mass in the neck and causes severe hypercalcemia and related symptoms, non-specific gastrointestinal manifestations, as well as renal and bone complications related to primary hyperparathyroidism (nephrolithiasis, impaired renal function, osteoporosis, bone pain, and pathologic fractures, etc.). Some PRTCs are however non-functioning tumors. The disease is parathyroid gland carcinoma (MONDO_0012004). Also known as: adenocarcinoma of parathyroid, adenocarcinoma of parathyroid gland, adenocarcinoma of the parathyroid, adenocarcinoma of the parathyroid gland, carcinoma of parathyroid, carcinoma of parathyroid gland, carcinoma of the parathyroid, carcinoma of the parathyroid gland.