What is a Thyroid?
The thyroid is a gland in the lower part of the neck that has two lobes and a narrow isthmus that connect the two lobes in the middle. It is literally wrapped around the trachea or windpipe; each lobe is approximately the size of a thumb. The thyroid produces a hormone that is important for our body’s day-to-day function and affects multiple organs.
Surgical problems that can arise in the thyroid include: nodules or masses; goiters; a multinodular condition; cancers; and overactive thyroid diseases where excessive thyroid hormone is produced, such as Graves’ disease.
Thyroid nodules are the most common problem that we see in our practice. They are usually discovered during a physical exam by your primary care physician or detected as an incidental finding on an X-ray done for another medical reason. Thyroid nodules are usually painless and are not tender. A blood test to check thyroid function can be performed as part of an evaluation.
There are two main types of thyroid cancer. Papillary thyroid cancer is the most common type and can usually be diagnosed by an ultrasound-guided fine-needle aspiration biopsy (see description below). Papillary cancers spread by local extension into tissues around the thyroid and by lymphatics to the lymph nodes around the thyroid. The second most common type of thyroid cancer is follicular cancer. Follicular nodules can be diagnosed by a fine-needle biopsy as well. Determining whether nodules are benign or malignant often requires surgical removal. Thyroid cancer tends to present itself in younger patients who are in their 20s to 50s. We do have thyroid cancer patients in their 70s, but this is an exception.
Causes, Risks & Prevention
Most thyroid nodules have no direct cause. However, radiation exposure, such as that experienced during nuclear reactor accidents (e.g., Chernobyl and Fukushima nuclear disasters) are associated with an increased risk of thyroid cancer. One patient was a medical missionary to the Chernobyl site and was diagnosed with thyroid cancer a few years after her visit there. Low-dose radiation can also affect the thyroid when given for other conditions. External radiation given for other cancers, such as breast or lung cancer, usually do not increase the risk of thyroid cancer.
A goiter can be an inherited and is very common in the southeastern US. The thyroid is enlarged and contains multiple nodules that can compress the trachea, press it to one side and even cause problems with swallowing. Occasionally, it will also be overactive, making too much thyroid hormone, and require removal by surgery.
Hashimoto’s thyroiditis is a very common autoimmune condition. Our immune system reacts to our thyroid tissue and, over time, destroys the gland and leads to low thyroid levels. It is the most common reason that patients must take a thyroid hormone replacement. There is no know cause or risk factor for Hashimoto’s.
It is recommended to avoid radiation exposure, especially low levels of repeated exposure, such as radiology or repeated use of X-rays before medical and dental procedures. Wearing lead protective aprons, shields and using good radiation safety is also a preventative practice.
Detection, Tests & Imaging
Thyroid nodules are commonly found during an examination by your primary care physician. Most gynecologists, internists and family practitioners are skilled in the examination of the thyroid. The other most common method of detection is finding the nodules in the thyroid on an X-ray done for another purpose. Most common examples are CT scans or MRIs of the cervical or thoracic spine or the chest. Some are found on carotid doppler studies used to evaluate carotid artery blood flow in the neck.
The best imaging modality for the thyroid is the ultrasound. There are criteria for interpreting a thyroid ultrasound called a TI-RADs classifications. Nodules are classified on a scale from 1, which is normal, to a 5, which is overtly suspicious for cancer. TI-RADs 2 and 3 nodules can usually be followed with a repeat ultrasound in 6 months to a year. TI-RADs 4 and 5 nodules need to have a fine needle aspiration biopsy that is done with ultrasound guidance. These procedures are done in our office under local anesthesia. The only part of the procedure that is painful is the injection to numb the skin and underlying tissue with a local anesthetic. The thyroid tissue does not contain sensory nerves, so when the needle is passed into the thyroid, it is not painful. Multiple, small back-and-forth motions are done with the needle in the nodule. Ultrasound is used to guide the needle, avoid other structures such as blood vessels, and ensure that the cells removed for testing are from the nodule of concern. The procedure only takes 15 to 20 seconds. The pathology report is usually complete within 48 to 72 hours. This needle biopsy can be used to guide the decision-making process regarding surgical removal of thyroid nodules or masses.
Thyroidectomy may involve the removal of a lobe or the entire gland. Sometimes, the only way a nodule can be defined as benign or malignant is to remove it surgically and have the entire lobe containing the nodule examined by the pathologist.
Thyroid surgery is a relatively safe procedure and is not associated with many risks or complications. Bleeding in the operative site is unusual, and sometimes a drain may be left in the neck to signal bleeding if it occurs. The drain is usually removed the first morning after the surgery. The risk of infection is very low. The two main risks associated with thyroid surgery are injury to one or both of the nerves to the larynx or vocal cords. These are called the recurrent laryngeal and superior laryngeal nerves. The recurrent laryngeal courses behind the the thyroid from the lower neck into the trachea. It must be carefully protected during the surgical removal of a thyroid lobe. Sometimes, even in skilled hands, these nerves can be stretched or injured. Recovery of the nerve is typical, but in some instances there is permanent nerve damage. This can be corrected by a throat specialist, if needed. Another risk is damage to the parathyroid glands. These are four very small glands - about the size of a match head - in the neck behind the thyroid, two on each side. They control the level of blood calcium in the body and produce a hormone that keeps the calcium level in the blood at normal levels. Only one parathyroid gland is necessary for normal function, but with some large goiters or inflamed thyroids, all four glands can be damaged. This can also be temporary or permanent. If permanent damage to all four glands occurs, patients must take supplements for the remainder of their lives to keep their blood calcium at a normal level.
Thyroidectomy is done under general anesthesia and usually requires about one hour of surgical time for each lobe. Patients usually spend one night in the hospital and are discharged home the following day. The incision is made across the lower neck and can often be hidden in a wrinkle or crease in the skin. Pain associated with this surgery is minimal and most patients do not require narcotics for pain management. Sutures are almost always buried under the skin using a plastic surgery technique for closure. These sutures are absorbed and don’t need to be removed.
Patients that require thyroid biopsy can resume their normal activities the same day as the biopsy but should avoid strenuous activity until the following day. Recovery from thyroid surgery is complete by 2-3 weeks postoperatively. Swelling under the incision develops over the first 7-10 days postoperatively but resolves completely 4-6 weeks postoperatively. Pain is minimal and most patients can take full care of themselves the day they are discharged from the hospital.
Your physician will sometimes prescribe thyroid hormone replacement tablets to be taken daily or may prescribe medications to maintain calcium levels if your parathyroids were bruised or damaged during your surgical procedure. These medications are usually taken for about 10-14 days and then discontinued. Tylenol (acetaminophen) or Advil (ibuprofen) is usually adequate for pain management.
You may shower at home the day you are discharged from the hospital. The piece of tape or steristrips on your incision can be carefully removed at 5-7 days postoperatively. If they fall off before this time, this is not a problem. If you experience rapid swelling in the neck or under the incision, please call the office or the physician on call for the practice as this can be a sign of bleeding. This risk is usually over 48 hours after the surgery.
Temporary hoarseness or voice weakness can also develop after discharge and is usually resolved by the second week postoperatively. However, full voice recovery can take up to three months or longer. Bloodwork may be required postoperatively. Most primary care physicians are very comfortable managing thyroid hormone replacement, if it is needed. For a majority of patients, return to work and normal activity can occur at 2 to 3 weeks postoperatively.