Medullary thyroid cancer
（重定向自Medullary carcinoma of the thyroid）
Medullary thyroid cancer (MTC) is a form of thyroid carcinoma which originates from the parafollicular cells (C cells), which produce the hormone calcitonin. Medullary tumors are the third most common of all thyroid cancers. They make up about 3% of all thyroid cancer cases.