Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer that originates from the parafollicular cells, also known as C cells. These cells produce a hormone called calcitonin, which helps regulate calcium levels in the body. MTC can occur sporadically or as part of a genetic syndrome called Multiple Endocrine Neoplasia type 2 (MEN 2), which increases the risk of developing other endocrine tumors. Symptoms of MTC may include a noticeable lump in the neck, difficulty swallowing, or changes in voice. Diagnosis typically involves blood tests to measure calcitonin levels and imaging studies to assess the tumor's size and spread. Treatment often includes surgery to remove the thyroid gland, and ongoing monitoring is essential for managing the disease.