Parathyroid carcinoma in a patient with primary hyperparathyroidism mimicking parathyroid adenoma

Primary hyperparathyroidism caused by parathyroid carcinoma is extremely rare. Clinically, it is very challenging to differentiate between parathyroid carcinoma and adenoma. The correct diagnosis is made based on the histopathology of the resection specimen. This case report presents a woman in her 40s with body aches, knee joint pain, and fatigue, along with chronic kidney disease. Ultrasonography revealed a large hyperechoic lesion in the left parathyroid gland. Serum calcium, parathyroid hormone, urea, and creatinine levels were increased. The inferior parathyroid gland was surgically removed, and histopathological evaluation confirmed a diagnosis of parathyroid carcinoma. Unfortunately, many patients do not undergo complete resection due to a lack of a correct diagnosis during the initial surgery.