Medullary Thyroid Cancer: A Review

Thyroid cancer is a malignancy of the thyroid parenchymal cells. There are four main types of thyroid cancer: papillary thyroid cancer (PTC), follicular thyroid cancer (FTC), anaplastic thyroid carcinoma (ATC), and Medullary thyroid carcinoma (MTC). Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor of the thyroid gland derived from parafollicular C-cells that produce calcitonin (CT) and accounts for 5-8% of all thyroid cancers. It is responsible for a disproportionate number of thyroid cancer deaths because of the lack of adjuvant treatment beyond surgery. MTC may occur sporadically or be inherited. Hereditary pattern includes multiple endocrine neoplasia syndrome types 2A and 2B. The majority of MTC cases are sporadic, but a hereditary pattern is present in 20-30% of cases. RET mutations occur in over 90% of hereditary and 40% of sporadic MTC. Total thyroidectomy remains the standard treatment for MTC patients. Early diagnosis and treatment are necessary for a 100% cure rate.