Words to know: Thyroid cancer
- Anaplastic
- Cells that look very different from normal cells and grow very fast.
- Biopsy
- Removing cells or tissue to check for cancer under a microscope.
- Calcitonin
- A hormone made by C cells. It is a tumor marker for medullary thyroid cancer.
- Differentiated
- Cancer cells that still look and act a lot like normal cells.
- Endocrinologist
- A doctor who treats hormone and gland problems, including the thyroid.
- Fine needle aspiration (FNA)
- A biopsy that uses a thin needle to take cells from a lump.
- Levothyroxine
- A pill that replaces the hormone your thyroid normally makes.
- Lobectomy
- Surgery to remove one half (lobe) of the thyroid.
- Lymph nodes
- Small bean-shaped glands that are part of the immune system. Cancer can spread to them.
- MEN2
- An inherited syndrome caused by a RET gene change. It raises the risk of medullary thyroid cancer and some other gland tumors.
- Metastatic
- Cancer that has spread from where it started to other parts of the body.
- Nodule
- A lump. Most thyroid nodules are not cancer.
- Parathyroid glands
- Four tiny glands next to the thyroid that control calcium levels in the blood.
- Radioactive iodine (RAI)
- A treatment that uses radioactive iodine to destroy thyroid cells and some thyroid cancer cells.
- RAI-refractory
- Thyroid cancer that no longer responds to radioactive iodine.
- Recurrence
- When cancer comes back after treatment.
- Stage
- A way to describe how big the cancer is and how far it has spread.
- Targeted therapy
- Medicine that blocks a specific gene change or protein in cancer cells.
- Thyroglobulin
- A protein made by thyroid cells. After treatment, it is used as a tumor marker.
- Thyroidectomy
- Surgery to remove the thyroid gland.
- TSH
- Thyroid stimulating hormone. It tells the thyroid to grow and make hormone.
- TSH suppression
- Taking enough thyroid hormone to keep TSH low, which may slow cancer growth.
- Ultrasound
- A scan that uses sound waves to make pictures.
- Clinical trial
- A research study that tests new treatments in people.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.