The thyroid is a butterfly-shaped gland located at the base of the neck, just below the Adam's apple. It produces hormones that regulate the heart rate, blood pressure, body temperature and weight. Thyroid cancer occurs in the cells of the thyroid

Most cases of thyroid cancer can be cured with treatment.

Symptoms

In the early stage of the disease thyroid cancer doesn't cause any signs or symptoms. As it grows, it may manifest the following symptoms:

  • Changes to the voice, including increasing hoarseness
  • A lump that can be felt through the skin on the neck
  • Difficulty swallowing
  • Pain in the neck and throat
  • Swollen lymph nodes in the neck

Causes

It's not clear what causes thyroid cancer.

Thyroid cancer occurs when there are genetic changes (mutations) in the cells. The mutations allow the cells to grow and multiply rapidly. The cells also lose the ability to die, as normal cells would. The tumor is formed by the accumulating abnormal thyroid cells. They and can invade nearby tissues and spread throughout the body.

Treatment and prognosis are determined by the type of thyroid cancer. These are the types of thyroid cancer:

  • Papillary thyroid cancer.
  • Follicular thyroid cancer.
  • Medullary thyroid cancer.
  • Anaplastic thyroid cancer.
  • Thyroid lymphoma.

Risk Factors

Factors that may increase the risk of thyroid cancer include:

  • Exposure to high levels of radiation
  • Female sex.
  • Inherited genetic syndromes.

Complications

Thyroid cancer can return despite treatment, even when the thyroid is removed. This can happen if  the cancer cells spread beyond the thyroid before it is removed. Thyroid cancer recurs most often in the first five years after surgery, but also decades after the initial thyroid cancer treatment.

Prevention

Doctors aren't sure what causes most cases of thyroid cancer, so there is no way to prevent thyroid cancer in people who have an average risk of the disease. Adults and children with an inherited gene mutation that increases the risk of medullary thyroid cancer are often advised to have thyroid surgery to prevent cancer (prophylactic thyroidectomy).