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Thyroid cancer is a type of cancer that starts in the tissues of the thyroid gland.
In the early stages, thyroid cancer may not show signs or symptoms, but when cancer is in its advanced stage, an unusual lump may form making a person feel sick.
The most common early sign of thyroid cancer is a lump, nodule, or swelling in the neck.
Other early warning signs of thyroid cancer include:
- Fatigue
- Changes in voice or constant hoarseness
- Swollen glands in the neck
- A persistent cough (not caused by a cold)
Other possible symptoms of thyroid cancer include:
What is thyroid cancer?
Thyroid cancer is a type of cancer that starts in the tissues of the thyroid gland, located near either side of the trachea, below the cartilage called Adam’s apple.
The thyroid gland is a butterfly-shaped organ (with two lobes connected by a thin piece of tissue called isthmus) and helps produce several important hormones, including the thyroid hormone. This hormone controls body temperature, weight, heart rate, and energy levels. The thyroid gland produces calcitonin, which helps the body use calcium.
An estimate states that thyroid cancer accounts for about three percent of all new cancer cases.
4 types of thyroid cancer
- Papillary thyroid cancer: Most common type of thyroid cancer that affects a single lobe and grows very slowly.
- Follicular cancer: Another most common type found in people who do not consume enough iodine in their diet.
- Medullary cancer: A rare type that starts in a group of thyroid cells called C cells. C cells make calcitonin, a hormone that helps control the amount of calcium in the blood.
- Anaplastic cancer: A rare type of thyroid cancer that spreads rapidly into the neck and to other parts of the body.
Who gets thyroid cancer?
According to the American Cancer Society (ACS), thyroid cancer is more common in:
- The age group between 25 and 65 years
- People who are exposed to radiation in the head or neck area
- Women are three times more likely than men
- People who consume a low-iodine diet
What causes thyroid cancer?
Although the exact cause of thyroid cancer is not known, certain risk factors may increase an individual’s chance of developing the disease including:
- Inherited genetic conditions, such as a mutation of the RET gene, familial adenomatous polyposis, Gardner syndrome, Cowden disease, and Carney complex type I
- Family history of thyroid cancer in a parent or sibling
- Low-iodine diet
- Radiation exposure from radiation therapy
How is thyroid cancer diagnosed?
For an accurate diagnosis, the doctor may conduct a physical examination, analyze personal and family medical history, and manually palpate the neck and throat to check for abnormal growths or areas of swelling, including the thyroid and lymph nodes.
Other recommended tests may include:
- Blood tests: To check for high levels of certain hormones, such as
- Triiodothyronine (T3)
- Thyroxine (T4)
- Thyroid-stimulating hormone (TSH)
- Diagnostic tests:
- Ultrasound: Neck ultrasound helps locate any nodules on the thyroid.
- Chest X-ray: If the doctor suspects cancer has metastasized to the lungs.
- Magnetic resonance imaging (MRI) scan: An MRI scan creates highly detailed images of the thyroid and surrounding areas using magnets.
- Computed tomography (CT) scan or positron emission tomography (PET) scan: A CT scan uses contrast dye (injected or swallowed) that helps the doctor understand the size and location of cancer and whether it has metastasized to surrounding tissues. A PET scan is similar but uses an injection of radioactive sugar instead of contrast dye (both of which are mostly absorbed by cancerous tissues).
- Biopsy: If suspicious tissue is present, a small sample may be taken to confirm a diagnosis of cancer. A biopsy may be obtained via:
- Fine needle aspiration: A fine needle is inserted into a small, anesthetized area of the skin to remove the sample.
- Surgical biopsy: A surgical biopsy is done under general anesthesia to remove the nodule and a portion of the thyroid.
- Molecular testing of the nodule sample: This testing is done to identify the specific genetic makeup of the nodule or tumor using a tissue sample.
- Radionuclide scanning: A person is asked to swallow or is injected with a small amount of radioactive iodine (a tracer that is absorbed by the thyroid cells) that helps make these specific cells easier for the doctor to differentiate from other regions.
- Vocal cord examination: A laryngoscopy could be performed using a laryngoscope, a thin scope with a light and mirror to ensure the vocal cords are functioning properly.