Abstract: This case report details the clinical presentation of a 55-year-old male with a 9-month history of swelling in the right mandible.Imaging studies identified osteolytic lesions in the jaw,while laboratory investigations revealed severe hypercalcemia (Ca2+3.75 mmol/L) and markedly elevated parathyroid hormone (PTH) levels (2 095.00 pg/ml).A suspicious mass in the parathyroid gland was detected.Subsequent parathyroidectomy and histopathological examination confirmed the diagnosis of parathyroid carcinoma,characterized by capsular and vascular invasion.Postoperative normalization of calcium and PTH levels was observed,accompanied by significant clinical improvement.This case underscores the importance of considering parathyroid carcinoma,albeit rare,in the differential diagnosis of patients presenting with severe hypercalcemia and skeletal manifestations.Surgical resection remains the definitive curative approach for this condition.

Key words: parathyroid carcinoma; primary hyperparathyroidism