Giant Intrathyroidal Parathyroid Carcinoma Presenting as an Asymptomatic Hypercalcemia: A Case Report and Literature Review.

Parathyroid carcinoma (PC) is a rare endocrine malignancy characterized by uncontrolled secretion of parathyroid hormone (PTH). This article presents a case of a giant PC that was entirely located within the thyroid gland and was initially misdiagnosed as a thyroid nodule. Our case is noteworthy for the absence of clinical symptoms and the markedly elevated serum calcium and PTH levels. We provide a detailed description of the patient's imaging findings and systematically review the diagnostic and therapeutic modalities of PC.