medullary thyroid carcinoma
Also written as: MTC — medullary thyroid carcinoma
Thyroid cancer arising from parafollicular C cells that produce calcitonin, often associated with hereditary syndromes.
Full Definition
Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor arising from the parafollicular C cells of the thyroid gland, which normally produce calcitonin. Unlike follicular cell-derived thyroid cancers, MTC does not respond to radioactive iodine therapy and has distinct biological behavior. Approximately 25% of cases are hereditary, associated with MEN2A or MEN2B syndromes and RET proto-oncogene mutations. Elevated calcitonin levels serve as both a diagnostic marker and monitoring tool. Treatment involves total thyroidectomy with central lymph node dissection, and prophylactic thyroidectomy is recommended for genetic carriers.
Usage
Usage note: Commonly abbreviated as MTC; distinguish from other thyroid carcinoma types in documentation.
In Context
- "Medullary thyroid carcinoma was suspected due to markedly elevated serum calcitonin levels." — endocrinology consultation
- "Hereditary medullary thyroid carcinoma requires genetic counseling and family screening." — genetics clinic note