Final answer:
Medullary thyroid cancer arises from parafollicular cells, or C cells, in the thyroid gland which produce calcitonin. This type of cancer is less common than other thyroid cancers and is unique due to the origin of the cell type.
Step-by-step explanation:
Medullary thyroid cancer originates from a specific type of cells in the thyroid gland known as parafollicular cells, or C cells. These cells are responsible for producing the hormone calcitonin, which plays a role in calcium homeostasis. Unlike the follicular cells of the thyroid, which absorb iodine to produce thyroid hormones, the C cells are distinct in their function and structure. When these parafollicular cells grow uncontrollably, it can lead to the formation of medullary thyroid cancer. This type of cancer is less common than other thyroid cancers that arise from follicular cells. It's important to recognize that tumors may be benign, which remain localized, or malignant, the latter of which can spread to other parts of the body.