The thyroid gland regulates metabolism, hormones, and body temperature. It is located below the Adam’s apple or larynx.
Thyroid nodules are abnormal tissue growths that form on the gland. They are usually quite harmless; in fact, it is unusual for thyroid nodules to even cause symptoms. Tests can determines the potential risk of a nodule, and treatment options depend upon the type of nodule that is present.
What are the Types of Thyroid Nodules?
- Colloid Nodule: The most common and benign. Comprised of one or more growths, colloid nodules may grow quite large but are still harmless.
- Follicular Adenoma: A benign, encapsulated tumor found on the thyroid gland.
- Thyroid Cyst: Nearly all thyroid cysts are simple, fluid-filled and benign.
- Inflammatory Nodule: These nodules result from repeated inflammation to the thyroid gland. Inflammatory nodules are sometimes painful, but are not always.
- Thyroid Cancer: Fortunately, this is very rare. Thyroid nodules are malignant less than 5% of the time.
- Multinodular Goiter: Most common in elderly patient, a multinodular goiter is a several nodules clustered together. A goiter can grow quite large but will remain benign.
- Hyperfunctioning Thyroid Nodule: Hyperfunctioning nodules act as a second thyroid by secreting hormones into the bloodstream. This causes an excess of certain hormones, leading to hyperthyroidism.
What Causes Thyroid Nodules?
At times, a person’s thyroid tissue begins to grow and form one or more nodule. Why does this happen in one person and not in another? The exact medical reason is not known, although some potential risk factors have been identified:
- Iodine Deficiencies: Nodules are seen more often in those with iodine deficiencies, or in those who come from families in which it exists. The thyroid absorbs all of the body’s iodine.
- Heredity: A family history of thyroid or endocrine cancer is a strong indicating factor.
- Genetic Defects: Genetic defects linked to TSH (Thyroid Stimulating Hormone).
- Age: Risk for thyroid nodule development increases as a person nears the aging process, and this is particularly true with goiters.
- Radiation Exposure: Radiation exposure from medical equipment seems to carry a higher risk of nodules, particularly if the radiation was absorbed around the head or torso area.
- Gender: Women are more likely to develop nodules.
- Hashimoto’s Disease: A disorder in which the immune system attacks the thyroid gland, causing hyperthyroidism.
- Other Thyroid Conditions: Preexisting issues such as chronic inflammation of the gland or thyroiditis are at high risk of developing nodules.
What are The Symptoms of Thyroid Nodules?
Though mostly asymptomatic, nodules can occasionally cause discomfort or pain. It is possible for nodules to grow large enough to be seen from the side or even front of the neck. Breathing and swallowing problems can occur, and some patients may also experience an unexplained voice change or persistent hoarseness.
Hyperfunctioning nodules produce symptoms of hyperthyroidism, some of which are:
- Weight loss
- Heart palpitations
- Sensitivity to light
- Vision problems
Nodules caused by Hashimoto’s disease can create symptoms of hypothyroidism:
How are Thyroid Nodules Diagnosed?
It is very common for a thyroid nodule to be diagnosed on accident during a routine exam. If a doctor thinks a nodule is present, a more thorough manual exam will be done of the neck area.
When there is a thyroid nodule present, one or more tests will need to be administered. The first priority of these tests is to make sure the nodule is not cancerous. The second is to determine how well the thyroid is functioning.
- Fine Needle Aspiration for Cytology – The nodule will need to be biopsied, in order to see if it is malignant or benign. A very fine needle is injected into the nodule, where its cells are removed so they can be examined.
- Ultrasound – This test uses high-frequency sound waves to give a visual picture of a thyroid nodule. Results can determine, for instance, between a malignant nodule and a harmless cyst. Ultrasound can be very helpful if a doctor and patient need to know whether or not to proceed with a needle biopsy.
- MRI and CT Scan – Thyroid nodules are not usually detectable with either of these methods; however, sometimes a nodule is “substernal” (located beneath a sternum) and may be large enough to be detected by MRI or CT.
- Thyroid Isotope – A radioactive scan of the thyroid nodule. The patient is given a small oral dose of radioactive iodine; when the iodine and radiation passes through the thyroid, the absorption process is studied. Thyroid and nodule tissue show as “hot,” “warm,” or “cold” on the scan. Nodule tissue that is “cold,” has a moderate rick of being cancerous.
What are The Treatments Options for Thyroid Nodules?
- Thyroid Hormone Suppression Therapy – Medication is used to combat the TSH hormone excess in a patient’s body, which is meant to reduce the size of the nodule.
- Radioactive Iodine Taken Orally – Radioactive iodine capsules are swallowed; when the thyroid absorbs the radiation, the excess thyroid tissue (nodules) is destroyed over time.
- Thyroidectomy – Surgery in which the thyroid is partially or entirely removed because of thyroid cancer. Since the thyroid is necessary to live, daily hormone treatment is necessary if the gland was removed entirely.
Thyroid nodules are harmless most of the time, with approximately 95% tested as benign.
Thyroid screening is recommended to those with higher risk probability for nodules; a doctor will simply examine the thyroid by hand and feel for any enlargements.