The Cell Type Determines the Treatment Path
Most thyroid cancers are differentiated cancers that arise from follicular cells. Papillary cancer is the most common; follicular and oncocytic—formerly Hürthle-cell—cancers are less common. Medullary thyroid cancer begins in calcitonin-producing C cells, while anaplastic thyroid cancer is rare, fast-growing and medically urgent.
Papillary, Follicular and Oncocytic
These cancers may be treated with surgery, selective radioactive iodine and individualized thyroid-stimulating-hormone suppression. Risk ranges from indolent to aggressive.
Calcitonin, CEA and RET
Radioactive iodine does not treat medullary thyroid cancer. Germline RET testing is important because the diagnosis may be part of inherited MEN2 syndrome.
Urgent Molecular Testing
Rapid pathology confirmation and BRAF V600E testing are essential. Airway, surgery, radiation and systemic therapy decisions often need a specialized multidisciplinary team.
Selected Very-Low-Risk Tumors
Some small papillary thyroid cancers can be monitored rather than treated immediately when location, imaging, patient preference and reliable follow-up make surveillance appropriate.

