Thyroid Surgery

The thyroid gland is at the base of the throat. It has two lobes, one on the right side and one on the left. The thyroid gland makes important hormones that help the body function normally.

Thyroid Nodule

Thyroid nodules are lumps which commonly arise within an otherwise normal thyroid gland. Most thyroid nodules cause no symptoms at all.

One a thyroid nodule is discovered, it is necessary to prove if it is benign (non-cancerous) or malignant (cancerous). 95% of thyroid nodules are benign, and therefore, only 5% of thyroid nodules are malignant.

Fine needle aspiration (FNA) is the first, and in the vast majority of cases, the only test required for the evaluation of a solitary thyroid nodule Thyroid fine needle aspiration (FNA) is a safe, effective, and easy way to determine if a nodule is cancerous. The needle is placed into the nodule several times and cells are aspirated into a syringe. The cells are placed on a microscope slide, stained, and examined by a pathologist. The nodule is then classified as nondiagnostic, benign, suspicious or malignant (cancer).

Benign nodules can be watched and treated by non-surgical medical management.  

Malignant nodules require surgical removal of all or part of the thyroid gland.

Nondiagnostic indicates that there are an insufficient number of thyroid cells in the aspirate and no diagnosis is possible. A nondiagnostic FNA should be repeated, as a repeat FNA will make a diagnosis approximately 50% of the time.

Suspicious classification makes up approximately 10% of FNA’s. The thyroid cells of these FNA’s are neither clearly benign nor malignant. Surgery is recommended for the treatment of thyroid nodules from which a suspicious aspiration has been obtained.

If a diagnosis cannot be made from the fine-needle aspiration, the doctor may operate to remove the nodule. A pathologist then checks the tissue for cancer cells.

Goiter

Goiter refers to enlargement of the thyroid which is not associated with overproduction of thyroid hormone or malignancy. There are a number of factors which may cause the thyroid to become enlarged: a diet deficient in iodine or an increase in thyroid stimulating hormone (TSH) in response to a problem in normal hormone synthesis within the thyroid gland.

Surgical Treatment of Goiters

  • Most small to moderate sized goiters can be treated by providing thyroid hormone in the form of a pill. Patients who do not respond to thyroid hormone therapy are often referred for surgery if it continues to grow.
  • A more common indication for surgical removal of a goiter is to remove almost all of the thyroid gland in order to improve symptoms a patient may be experiencing such as  cough, voice changes, choking, difficulty swallowing.
  • Suspicion of malignancy in an enlarged thyroid is an indication for removal of the thyroid.

Thyroid Cancer

Thyroid cancer is a disease in which cancer (malignant) cells are found in the tissues of the thyroid gland. Certain factors may increase the risk of developing thyroid cancer.

  • Thyroid cancer occurs more often in people between the ages of 25 and 65 years.
  • People who have been exposed to radiation or received radiation treatments to the head and neck during infancy or childhood have a greater chance of developing thyroid cancer.
  • People who have had goiter or a family history of thyroid disease have an increased risk of developing thyroid cancer.
  • Thyroid cancer is more common in women than in men.

There are four main types of thyroid cancer papillary, follicular, medullary, and anaplastic.

Stages

The TNM method is the most universally used staging method and applies to both papillary and follicular thyroid cancers. TNM stands for:

T: Tumor size (in cm)

  • T1 if the tumor is less than 1cm
  • T2 if it is 1-4 cm
  • T3 if it is greater than 4 cm
  • T4 if the tumor extends beyond the thyroid gland

N: Node metastasis – presence or absence of lymph node metastases (meaning has the cancer spread to the lymph nodes in the neck).

  • N0 if none of the lymph nodes are affected
  • N1 If the cancer has spread to the lymph nodes

M: Distant metastases (meaning has the cancer spread beyond the neck to other areas of the body like the lung or bone)

  • M0 if the cancer has not spread outside of the neck region
  • M1 if there is distant metastases

Based on these three categories, the cancer is assigned a Stage of 1, 2, 3 or 4. Stage 1 is the least advanced form of cancer with the best prognosis, and Stage 4 is the most advanced category. The table below shows the likelihood of a local recurrence (or recurrence of thyroid cancer in the neck region), distant recurrence (recurrence of cancer in other areas of the body), and mortality (death) based on the stage of a given tumor.

Stage

Age < 45

Age > 45

Local recurrence

Distant Recurrence

Mortality

I

Any T Any N M0

T1 N0 M0

5.5%

2.8%

1.8%

II

Any T Any N M1

T2 N0 M0
T3 N0 M0

7%

7%

11.6%

III

-

T4 N0 M0
Any T Any N M1

27%

13.5%

37.8%

IV

Any T Any N M0

T1 N0 M0

5.5%

2.8%

1.8%

Surgery is the most common treatment for thyroid cancer. The surgeon may remove all or part of the thyroid. The type of surgery depends on the type and stage of thyroid cancer, the size of the nodule, and the patient’s age.

Surgical Operations for Thyroid Diseases

Thyroid Lobectomy. One-half of the thyroid is removed. This operation is generally performed for worrisome thyroid nodules or nodules which are non-diagnostic after FNA.

Subtotal Thyroidectomy. Almost the entire thyroid is removed. Some thyroid is left to provide function. This operation is generally performed for goiters.

Total Thyroidectomy. The entire thyroid gland is removed. This operation is generally performed for all thyroid cancers regardless of the type.