Goiter

A thyroid gland that is enlarged is called a goiter. There are a variety of reasons for a goiter to develop, and all the causes take time to enlarge the thyroid and turn it into a goiter. Goiter development falls into three categories:

  • Hyperplastic – which happens either because the gland is working harder to make hormone and grows, or causes growth of the entire gland.
  • Inflammatory – which is caused by the immune system either attacking the thyroid by mistake or causing inflammation and swelling in the thyroid.
  • Nodular – caused by benign or cancerous tumors developing in the thyroid that causes growth of the thyroid. This can be due to a single nodule or multiple nodules (multinodular goiter). And the thyroid enlargement in these cases happens in the areas where the tumor/nodule is growing.

The following is a list of reasons for goiters to develop:

Iodine deficiency – Iodine is an essential component of thyroid hormones. In areas where iodine is deficient, there will be less thyroid hormones (T3 & T4) in the blood stream. As a consequence, the pituitary gland will produce more TSH (Thyroid Stimulating Hormones), TSH in turn stimulates the thyroid gland to work harder to make hormones and over time stimulates it to get bigger. Uncommon in the countries that use iodized salt, like the US.

Inflammation – Thyroiditis is an inflammatory condition that causes the thyroid gland to swell, and become painful. It also can cause the gland to work less and produce less hormone.

Hashimoto’ s Disease – Also called Hashimoto’s Thyroiditis is an immune condition when the immune system by mistake attacks the thyroid causing it to work less with each attack. Pituitary gland senses the decreased T3 & T4 levels and produces excess TSH which cause the thyroid to grow in time.

Grave’s Disease – This condition is caused by the immune system producing an antibody (TSI – Thyroid Stimulating Immunoglobulin), that attaches to the same area that TSH would attach and stimulates the thyroid to not only release more hormone but also grow. These patient have symptoms of hyperthyroidism along with goiter.

Single Thyroid – When a nodule gets large enough to make the thyroid bigger, wider, or longer then it is considered to be a goiter. These nodule can be benign (adenoma) or malignant (carcinoma).

Single Thyroid – When a nodule gets large enough to make the thyroid bigger, wider, or longer then it is considered to be a goiter. These nodule can be benign (adenoma) or malignant (carcinoma).

Multinodular Goiter – This occurs when there are multiple nodules which can cause one or both sides of the thyroid to get bigger.

Symptoms

A goiter that is small and not pressing on the surrounding tissue is usually not a problem, unless the amount of hormones it produces is too low or excessive. Larger goiters can press on the breathing tube (trachea) or swallowing tube (esophagus), which may lead to shortness of breath, coughing or difficulty swallowing.

Diagnosis

Often a goiter or nodule is identified when your physician feels your neck. Alternatively the may be seen when a neck scan is done looking for other issues and the thyroid abnormality is seen incidentally. To further work up a goiter to figure out the reason for it the following tests may be done:

  • Thyroid hormone blood tests – checking the level of TSH, Free T3 & Free T4 will give you an indication wether the thyroid is working appropriately or is it over or under active.
  • Thyroid antibody blood tests – if the thyroid is overactive then a blood test for TSI (Thyroid Stimulating Immunoglobulin) is done to see Grave’s Disease is present. If the thyroid is under active then TPO-Ab (Thyroid Peroxidase Antibody) test is done to see if Hashimoto’s Thyroiditis is present.
  • Ultrasound – Will show the size and dimensions of the thyroid gland as well s the breathing tube. It will also show if there are any nodules in the thyroid, the size of it, and if the nodule has any suspicious features.
  • Needle biopsy – If the ultrasound reveals any suspicious nodule then an ultrasound guided fine needle aspiration (FNA) or biopsy can be done which is a simple procedure done in the office under local anesthesia.
  • Thyroid Scan – This is a nuclear scan that shows if parts or the entire thyroid is overactive. Specially important if the person is overproducing thyroid hormones and also has a nodule or nodules on ultrasound to determine if the extra thyroid hormone is produced by the nodule (toxic nodule) or the entire gland (Grave’s Disease).

Treatment

Treatment of goiter is always based on the cause of the goiter, it’s size and the symptoms it causes. Some goiters are treated with medications, others require surgery, and rarely some are treated with radioactive iodine (RAI).

RFA is also an alternative option to reduce the size of the thyroid without surgery.