Medullary thyroid carcinoma (MTC) is a type of thyroid cancer that arises from the parafollicular cells (also known as C cells) in the thyroid gland. These cells produce a hormone called calcitonin, which helps regulate calcium levels in the body. MTC is different from the more common types of thyroid cancer, such as papillary and follicular thyroid carcinomas, which originate from the follicular cells that produce thyroid hormones.
MTC is less common than other types of thyroid cancer, accounting for about 2-3% of all thyroid cancers. It is typically diagnosed in older adults, with a median age at diagnosis of around 50 years. MTC can be sporadic (occurring without a family history) or inherited as part of multiple endocrine neoplasia type 2 (MEN2) syndrome, which is associated with the presence of other endocrine tumors, such as pheochromocytomas and parathyroid adenomas.