What is the Thyroid Gland?
The thyroid gland is located on the front of the neck between the "Adams apple" (larynx) and the top of the breast bone. It has a right and left lobe connected by a small bridge called the isthmus. The thyroid gland functions as the body's "thermostat". It makes a substance called thyroxin or "thyroid hormone". This hormone has many functions in the body, including controlling energy expenditure. A person can survive without a thyroid gland but would need to take supplemental thyroid hormone tablets.
About thyroid nodules
All lumps or nodules in the thyroid gland have to be investigated one way or another. Fortunately, only certain kinds of nodules develop into cancer.
The tests that are useful are:
Thyroid function tests
These tests help determine which kind of nodule you have. A typical cancer might be cold on scan, solid on ultrasound, and with normal thyroid function tests. However, not all cancers follow these exact criteria. Fortunately, only about 20% of thyroid nodules contain cancer. The rest are benign growths. Determining which are cancer and which are not is the main diagnostic issue.
There are two common types of thyroid cancer: papillary and follicular. These both have very good chances of being cured. After removal of the thyroid it rarely comes back, and almost never spreads. Even if it does come back, it has a tendency to come back in the same general location and often can be cured by additional surgery.
Needle biopsy of the thyroid
If a scan and ultrasound indicate that a patient has a nodule which might be a cancer, then we will need to biopsy the nodule one way or another. One type of biopsy is done with a small needle which is inserted into the nodule to remove a few cells. Often, this is done with ultrasound guidance to make sure the center of the nodule is biopsied. These cells are spread on a microscope slide and examined under the microscope by the pathologist. This is very similar to the way a Pap smear is done. It's accuracy is over 95%, but not quite 100%.
When we do a needle biopsy, we will usually get one of the following
1- Papillary nodule -benign
2- Papillary nodule -malignant
3- Follicular nodule -can't tell if it's benign or malignant
4- Other unusual finding
5- Can't really tell at all
If we get a report indicating #2,3, 4, or 5 then surgical removal of the nodule is necessary. If we get answer #1 the nodule does not need to be removed, as long as we are willing to accept the small percentage chance that the needle biopsy is misleading. If we are not willing to accept this, then there really isn't a good reason to do the needle biopsy test in the first place since all five answers lead to surgical removal as the next step. There are varying opinions among physicians regarding the use of needle biopsy in the diagnosis of thyroid nodules. However, the only way to be absolutely sure of the diagnosis is to remove the nodule.
In order to biopsy a nodule in the thyroid we usually remove the half of the thyroid gland containing the nodule. Removing half the gland is actually safer and easier than trying to remove the nodule from within the gland. The area removed is given to a doctor called a pathologist who examines it under a microscope. For a rapid diagnosis, the pathologist can quick-freeze a portion of the lump, and make very thin slices which he can look at under the microscope. This only takes about 15 minutes and is called a frozen section. This can give us a diagnosis most of the time.
Occasionally, the pathologist has to say that he is not sure of the frozen section diagnosis and that we will have to wait for the permanent sections, which take two days to process. This takes longer because instead of freezing the tissue, it is imbedded in paraffin (or wax). This process gives a clearer microscopic slide. If the biopsy of the nodule reveals cancer then the entire gland is usually removed. However, because of the limitations of frozen sections there are times that we don't know that the nodule was cancer until we get our permanent section report a couple of days after the operation. If this happens, an additional operation to remove the rest of the thyroid may be indicated.
About the operation
The operation can take anywhere from one to three hours. The incision for a thyroidectomy is crosswise, just beneath the "Adam's apple". The entire gland will be examined and felt, and a decision will be made regarding how much of the thyroid to remove. All or part of the gland will be removed depending on our findings. The incision will then be closed.
Sometimes it is necessary to leave a small plastic tube in place to drain the area where the gland was removed. This is a few days after the operation.
Potential problems with the operation
The nerves to the vocal cords (recurrent laryngeal nerves) are right behind the thyroid gland. These nerves must be visualized and separated from the gland. These nerves are very small and fragile. There is one on each side. If one of these nerves is damaged a patient would have temporary or permanent loss of function of that vocal cord. This would result in hoarseness if it happened to one nerve. If the very unusual circumstance occurred where both nerves were permanently injured, a person would not be able to talk, and would require a tracheostomy to breathe. This is a very rare circumstance that usually happens in situations involved with removal of very large glands or tumors.
There are four very tiny glands called the parathyroid glands which are also on the back of the thyroid. They make a hormone which controls the level of calcium in the blood. They are about the size of sesame seeds. The body only needs one healthy parathyroid gland in order to have adequate calcium control. If all of these glands were injured or removed a person would need to take vitamin D and calcium supplementation every day to control the blood level of calcium. This problem can also occur on a temporary basis from manipulation of the glands during the operation. If an operation consists of removal of only one side of the thyroid it would be very unusual to have a problem with this.
If it is necessary to remove the entire thyroid gland a patient would have to take thyroid hormone replacement tablets on a daily basis. We only remove the entire thyroid gland if it is absolutely necessary.
The surgeons at Evergreen Surgical have had many years of experience successfully taking care of patients with thyroid nodules. We are happy to see patients from out of town for surgery. No referral is necessary, so patients can call us directly at 715-832-1044, or send us an email.