The thyroid gland performs the important function of producing thyroid hormone. This hormone is the key regulator of metabolism in every cell in the body. Thyroid gland disorders can be classified into several types, including malfunction of hormone production, autoimmune diseases, abnormal size of the gland, and thyroid tumors. Treatment of these disorders usually involves a team of physicians, including an endocrinologist (medical gland specialist) and sometimes a surgeon, if removal of all or part of a thyroid gland is deemed necessary.

Evaluation of Metabolic Thyroid Function

Thyroid glands are tightly regulated in terms of the amount of thyroid hormone they produce. The status of a thyroid gland’s function is best determined by blood tests. The gold standard test involves measuring the TSH (thyroid stimulating hormone) level. This hormone is secreted by the pituitary gland at the base of the base in response to the metabolic needs of the body. A high level of TSH indicated that the body needs more thyroid hormone to be produced (hypothyroidism). Conversely, a low level of TSH indicates that too much thyroid hormone is present (hyperthyroidism). Additional blood tests can measure the actual levels of thyroid hormone in the blood stream (T3, T4, free T4 index). Interpretation of these results can be confusing and is best left to physicians who specialize in thyroid diseases. The symptoms of thyroid dysfunction are many, and are often confused with other conditions. Hormone supplementation is used to treat hypothyroidism. Medication, radioactive iodine therapy and sometimes surgery are needed to control hyperthyroidism.

Autoimmune Thyroid Disorders

The thyroid gland is susceptible to injury from the body’s immune system through a process called autoimmune injury. This is a genetically predisposed group of conditions that involves many thyroid patients. Common examples of autoimmune thyroid diseases include Hashimoto’s thyroiditis (causing hypothyroidism), Graves disease (causing hyperthyroidism), and formation of some lumps and bumps in the thyroid, known as nodules. Specific blood tests are able to accurately diagnose these conditions. Treatment options are determined by the presence of hyper or hypothyroidism. Surgery is frequently indicated to remove a thyroid gland in the presence of Graves disease.

Enlargement of the Thyroid Gland

The common term used to describe a large thyroid gland is goiter. Goiters arise for a variety of reasons, including genetic predisposition, lack of iodine in the diet, autoimmune disorders, and development of nodules, cysts or tumors in the gland itself. A goiter typically presents as a painless mass in the neck. Some goiters can grow behind the breastbone and remain hidden from view. When a goiter is very large, it can interfere with swallowing and breathing in addition to causing unsightly fullness of the neck. Large goiters are typically removed surgically.

Thyroid Nodules

The most common reason for undergoing thyroid surgery is the presence of a mass or nodule in the thyroid gland. Nodules arise for several reasons, including autoimmune inflammation within the gland, development of a fluid-filled cyst, or the growth of a tumor in the thyroid gland. The vast majority of nodules arise for benign reasons. The estimated incidence of malignancy in a solitary nodule in the general population is around 4%.

Nodules are typically diagnosed either by clinical examination in the physician’s office or as a finding on an imaging study such as Xray, ultrasound, CT scan or MRI scan of the head and neck or chest. State of the art evaluation of any nodule includes diagnostic ultrasound to determine size, location and number of nodules present, followed by fine needle biopsy to obtain a microscopic tissue sample for analysis. Fine needle biopsy is sometimes carried out with the assistance of ultrasound or CT localization if the nodule(s) in question cannot be easily felt by hand. Nuclear medicine studies are no longer considered necessary for routine evaluation of nodules.

Thyroid Tumors

Tumors of the thyroid gland fall into two categories – benign and malignant. Fortunately, the majority of all thyroid tumors are benign (>80%). Diagnosis of tumors requires tissue analysis, usually in the form of removal of that portion or lobe of the thyroid gland containing the suspicious nodule. Fine needle biopsy can only give an index of suspicion for the presence of a thyroid cancer.

There are four types of thyroid cancer: papillary, follicular, medullary, and anaplastic carcinomas. The only one that can be diagnosed with a reasonable degree of certainty from fine needle biopsy is papillary carcinoma. Frequently, abnormal microscopic findings on the needle biopsy necessitate surgery to make the formal diagnosis. Treatment of choice for all thyroid cancers includes removal of the entire thyroid gland (total thyroidectomy). Depending on the cancer type, size and other areas of involvement at the time of diagnosis, additional treatments such as radioactive iodine therapy and very rarely chemotherapy and radiation therapy may be necessary. Many variables need to be considered with treatment of these cancers. Detailed discussions with both the endocrinologist and head and neck surgeon are necessary for a full understanding of management and prognosis.

Thyroid Surgery

Surgery on the thyroid gland is performed for the following reasons: 1. Removal of a symptomatic goiter 2. Removal and analysis of thyroid nodule(s) or tumors and 3. Treatment of hyperthyroidism unresponsive to medical therapy. The surgery can involve removal of one half of the thyroid (lobectomy), removal of most of the gland (subtotal thyroidectomy), or removal of the entire gland (total thyroidectomy). In cases where thyroid cancer is present, removal of lymph nodes in the neck may also be required (neck dissection).

All thyroid operations are performed while the patient is asleep under general anesthesia. An incision is made in the midline of the neck between the Adam’s apple and the notch above the breastbone. The size of the incision is proportionate to the size of the gland itself, usually near 2 inches in length for the average case, but longer for large goiters. The incision is placed either in a natural skin crease, or parallel to one, so that it heals in a very cosmetically acceptable fashion after a plastic surgery style closure.

Several techniques are available to visualize the gland, including the use of endoscopes or fiberoptic cameras in certain cases (VAT or video assisted thyroidectomy) and other optics for purposes of magnification. Many other new advances are available for minimizing bleeding and risk of damage to surrounding tissues. Robotic surgery does not have a place in treatment of thyroid disease, at this time.

The surgeon’s biggest job during the procedure is to identify and preserve normal structures around the thyroid gland during its removal. Several structures, in particular, come into play with every thyroid operation. The first of these is a pair of nerves that supply function to various muscle groups controlling the activity of the vocal cords. The recurrent laryngeal nerves come up from the chest and run underneath each lobe of the thyroid on their way to the larynx. The superior laryngeal nerves run down the neck and enter the larynx adjacent to the upper part of each thyroid lobe. Injury to these nerves is rare in the hands of an experienced and skilled surgeon. If injury does occur, it is typically temporary in nature, yielding a hoarse voice for weeks to months. Permanent injury is even more rare, but can be rehabilitated in many cases through modern day reconstructive procedures and voice therapy.

The second set of structures intimately associated with the thyroid are the parathyroid glands. Most people (95%) have four parathyroid glands that are responsible for secreting parathyroid hormone. This hormone is responsible for maintaining calcium levels high enough in the bloodstream to keep muscles, the heart, and nerves functioning properly. Surgery may occasionally aggravate the function of the parathyroid glands causing them to not function effectively. A thyroid operation on only one half of the thyroid does not influence calcium levels, as the two parathyroids on the opposite side are untouched. A total thyroidectomy, however, has a small chance of causing malfunction of all four parathyroids, leading to low calcium levels (hypocalcemia). This is typically a temporary condition lasting weeks, but on very rare occasion may be permanent, necessitating daily calcium supplementation.

People are able to talk, eat and drink within hours after thyroidectomy. We keep our patients overnight in the hospital with a small surgical drain in the neck to prevent swelling in the wound. The drain is removed the next day and patients go home after lunch (23 hour stay). The only patients who stay longer than one day are those who manifest hypocalcemia requiring intravenous calcium supplementation.

Most patients are pleasantly surprised by the modest level of discomfort associated with the average thyroid operation. Tylenol is typically sufficient for pain relief after one or two days. A full week off work is necessary, but physical activity such as walking and range of motion exercises for the neck are encouraged. Normal exercise may be resumed in the second week after surgery. Patients who undergo removal of only a portion of their thyroid gland typically do not need supplemental treatment with thyroid hormone pills postoperatively. All patients undergoing a total thyroidectomy, however, will require a thyroid hormone pill on a daily basis.

The patients are seen one week after surgery on a postoperative visit. At that time, sutures are removed and tissue analysis reports are reviewed. A final postoperative visit occurs one month later. Patients with thyroid cancer may require additional visits to rule out recurrences of their tumors.