Thyroid Gland - How & Why

THYROID GLAND – HOW AND WHY?

Thyroid and Disorders

Thyroid Gland:

Thyroid is one of the endocrine glands, which makes hormones to regulate physiological functions in the body. This gland manufactures thyroid hormone, which regulates the rate at which a body carries on its necessary function. Some of the endocrine glands are the pancreas, the pituitary, the adrenal glands, the parathyroid glands, the testes, and the ovaries.

The thyroid gland is located in the middle of the lower neck, below the larynx (voice box) and just above the clavicles (collarbones). It is shaped like a “bow tie,” having two halves (lobes): a right lobe and a left lobe joined by an “isthmus.”

Abnormal Thyroid Gland:

Disease of the thyroid gland is very common, affecting millions of people in the world. The most common diseases are an over- or under-active gland. These conditions are called hyperthyroidism (e.g., Grave’s disease) and hypothyroidism. Sometimes the thyroid gland can become enlarged from over-activity (as in Grave’s disease) or from under-activity (as in hypothyroidism). An enlarged thyroid gland is often called a “goiter.” Sometimes an inflammation of the thyroid gland (Hashimoto’s disease) will cause enlargement of the gland.

Patients may develop “lumps” or “masses” in their thyroid glands. They may appear gradually or very rapidly. Patients who had radiation therapy to the head or neck as children for acne, adenoids, or other reasons are more prone to develop thyroid malignancy. A physician should evaluate all thyroid “lumps” (nodules).

How does a doctor make the diagnosis?

Taking a medical history and examining the neck makes the diagnosis of a thyroid mass. Specifically, a doctor will examine neck and lift up the chin to make the thyroid gland more prominent. Swallowing during the examination, helps to distinguish a thyroid mass from other lumps and bumps in the neck.Other tests that a doctor may order include:

1. An ultrasound examination of the neck and thyroid
2. Blood tests for thyroid function
3. A radioactive thyroid scan
4. A fine needle aspiration biopsy
5. A chest X-ray
6. A CT or MRI scan

Fine Needle Aspiration

If a lump in the thyroid is diagnosed, a doctor may recommend a fine needle aspiration biopsy. This is a safe, relatively painless procedure. A hypodermic needle is passed into the lump, and samples of tissues are taken. Often several passes with the needle are required. There is little pain afterward and very few complications occur from the procedure. This test gives the doctor more information on the nature of the lump in the thyroid gland and specifically will help to differentiate a benign from a malignant thyroid mass. Reliability of this test is about 90% meaning 10% of results may be wrong.

Treatment of Thyroid Disease

Abnormalities of thyroid function (hyper or hypothyroidism) are usually treated medically. If there is insufficient production of thyroid hormone, this may be given in the form of a thyroid hormone pill taken daily. Hyperthyroidism is treated mostly by medical means, but occasionally it may require surgical removal of the thyroid gland.

If there is a lump of the thyroid or a diffuse enlargement (goiter), the doctor will propose a treatment plan based on the examination and results of the test. Most thyroid “lumps” are benign. Often they may be treated with thyroid hormone, and this is called “suppression” therapy. The object of this treatment is to attempt shrinkage of the mass over time, usually three-six months. If the lump continues to grow during treatment, most doctors will recommend removal of the affected lump.

If the fine needle aspiration is reported as suspicious for or suggestive of cancer, then thyroid surgery is required.

This surgery is to remove part or all of the thyroid gland. It is performed in the hospital, and general anesthesia is usually required. Additional techniques like Tumescence reduces bleeding during operation. Usually the operation removes the lobe of the thyroid gland containing the lump and possibly the isthmus. A frozen section (an immediate microscopic reading) may or may not be used to determine if the rest of the thyroid gland should be removed. Sometimes, based on the result of the frozen section, the surgeon may decide to stop and remove no more thyroid tissue, or proceed to remove the entire thyroid gland, and/or other tissue in the neck. This is a decision usually made in the operating room by the surgeon, based on findings at the time of surgery. The surgeon will discuss these options with the patient preoperatively.

After surgery, one may have a drain (a tiny piece of plastic tubing), which prevents fluid from building up in the wound. This is removed after the fluid accumulation is minimal. Most patients are discharged one to three days after surgery. Complications after thyroid surgery are rare. They include bleeding, a hoarse voice, difficulty in swallowing, numbness of the skin on the neck, and low blood calcium. Most complications go away after a few weeks. Patients who have all of their thyroid gland removed have a higher risk of low blood calcium post-operatively. In case the voice changes after thyroid surgery and does not improve in 3 months additional procedures of phono surgery – Type I thyroplasty will help to get back the original voice.

Patients who have thyroid surgery may be required to take thyroid medication to replace thyroid hormones after surgery. Some patients may need to take calcium replacement if their blood calcium is low. This will depend on how much thyroid gland remains, and what was found during surgery. If they have any questions about thyroid surgery, clarify with the doctor and he or she will answer them in detail.