Parathyroid Carcinoma: A Diagnostic Challenge – A Case Report

Parathyroid carcinoma is a rare endocrine carcinoma, presenting as hypercalcemia with elevated parathyroid hormone (PTH) levels, and with renal and bone involvement. It is often misdiagnosed as parathyroid adenoma, resulting in conservative resection of the parathyroid gland and recurrence or metastasis after a few years. A 52-year-old, morbidly obese woman presented with asymptomatic hypercalcemia and elevated PTH. Ultrasound of the neck showed a cystic lesion adjacent to the right thyroid lobe. Sestamibi (MIBI) parathyroid scintigraphy showed increased radiopharmaceutical uptake by the right superior parathyroid gland without any enlarged or suspicious lymph nodes. She was diagnosed with primary hyperparathyroidism. She underwent right superior parathyroidectomy and en bloc right thyroid lobectomy due to suspicion of parathyroid carcinoma. The histological examination was consistent with parathyroid carcinoma. Parathyroid carcinoma is a rare disease with no clear diagnostic criteria. The curative treatment for parathyroid carcinoma is the initial en bloc resection. Therefore, early diagnosis is important and high clinical suspicion is warranted in patients with severe hypercalcemia and markedly elevated PTH, with or without palpable neck mass, and renal or bone involvement.