Thyroid Nodules & Surgery
Thyroid Specialist in Singapore
Dr. Leslie Koh is an experienced thyroid surgeon and thyroid specialist in Singapore. Thyroid nodules, both symptomatic and asymptomatic are common in Singapore, and the rate of cancer in these nodules has been increasing.
What are Thyroid nodules?
A thyroid nodule is an area of abnormal growth within the thyroid gland. The thyroid is a butterfly-shaped gland located at the base of the front of the neck. It produces thyroid hormone, which controls your metabolism, temperature regulation, and keeps your muscles and organs working properly.
Diseases of the thyroid, whether functional (hypothyroidism, hyperthyroidism) or structural (nodule, goiter, cancer), occur very commonly. Some people have a single nodule while others have multiple nodules within the gland. Thyroid nodules, which are particularly common in women, can be tiny, to very large in size.
What are the symptoms of a thyroid nodule?
Most thyroid nodules are non-cancerous, do not cause symptoms, and do not need any treatment. In some cases, however, because of the size, appearance (on radiology tests), or symptoms caused by the nodule, additional evaluation and treatment may be needed. The presence of a family history of thyroid cancer, exposure to radiation and some suspicious features on physical examination and ultrasound scan can increase the likelihood of thyroid cancer in a thyroid nodule.
Most thyroid nodules do not cause symptoms. Often, thyroid nodules are discovered incidentally during a routine physical examination or on imaging tests like CT scans or neck ultrasound done for completely unrelated reasons. Occasionally, patients themselves find thyroid nodules by noticing a lump in their neck while looking in a mirror, buttoning their collar, or fastening a necklace. Abnormal thyroid function tests may occasionally be the reason a thyroid nodule is found.
Thyroid nodules may produce excess amounts of thyroid hormone causing hyperthyroidism (see Hyperthyroidism brochure). However, most thyroid nodules, including those that cancerous, are actually non-functioning, meaning blood tests are usually normal. Rarely, patients with thyroid nodules may complain of pain in the neck, jaw, or ear. If a nodule is large enough to compress the windpipe or esophagus, it may cause difficulty with breathing, swallowing, or cause a “tickle in the throat”. Even less commonly, hoarseness can be caused if the nodule invades the nerve that controls the vocal cords but this is usually related to thyroid cancer.
How are thyroid nodules investigated?
The following tests can be performed to investigate a thyroid nodule:
- Blood tests, specifically Thyroid Function Tests (TFT)
- Nasoendoscopy to evaluate the movement of the vocal cords
- Imaging, specifically an ultrasound to evaluate the size and appearance of the nodule, and whether there are any suspicious features
- A fine needle aspiration (FNA) biopsy, which is a safe, relatively painless procedure. In this procedure, a small needle is passed into the lump, and tissue samples containing cells are taken and then sent to a pathologist for testing.
What results can i expect from an Fine Needle Aspirate (FNA) Biopsy?
The report of an FNA biopsy will usually indicate one of the following findings:
The nodule is benign (noncancerous)
This result is obtained in up to 80% of biopsies. The risk of overlooking a cancer when the biopsy is benign is generally less than 3%. Generally, benign thyroid nodules do not need to be removed unless they are causing symptoms like choking or difficulty swallowing. Follow up ultrasound exams are important. Occasionally, another biopsy may be required in the future, especially if the nodule grows over time.
The nodule is malignant (cancerous) or suspicious for malignancy.
A malignant result is obtained in about 5% of biopsies and is most often due to papillary thyroid cancer, which is the most common type of thyroid cancer. A suspicious biopsy has a 50-75% risk of cancer in the nodule. These diagnoses will most likely require require surgical removal of the thyroid.
The nodule is indeterminate.
This is actually a group of several diagnoses that may occur in up to 20% of cases. An indeterminate finding means that even though an adequate number of cells was removed during the fine needle biopsy, examination with a microscope cannot reliably classify the result as benign or malignant.
The biopsy may be indeterminate because the nodule is described as a Follicular Lesion. These nodules are cancerous 20-30% of the time. However, the diagnosis can only be made by surgery. Since the odds that the nodule is not a cancer are much better here (70-80%), only the side of the thyroid with the nodule is usually removed. If a cancer is found, the remaining thyroid gland usually must be removed as well. If the surgery confirms that no cancer is present, no additional surgery to “complete” the thyroidectomy is necessary.
The biopsy may also be indeterminate because the cells from the nodule have features that cannot be placed in one of the other diagnostic categories. This diagnosis is called atypia, or a follicular lesion of undetermined significance. Diagnoses in this category will rarely contain cancer. However, surgical biopsy to remove half of the thyroid containing the nodule is usually recommended.
The biopsy is non-diagnostic or inadequate
This result is obtained in less than 5% of cases when an ultrasound is used to guide the FNA. This result indicates that not enough cells were obtained to make a diagnosis but is a common result if the nodule is a cyst. These nodules may require reevaluation with second fine needle biopsy, or may need to be removed surgically.
How Are Thyroid Nodules Treated?
All thyroid nodules that are found to contain a thyroid cancer, or that are highly suspicious of containing a cancer, should be removed surgically. Removal of half of the thyroid gland is termed a hemi-thyroidectomy, and removal of the entire thyroid gland is termed a total thyroidectomy. Most thyroid cancers are curable and rarely cause life-threatening problems.
Thyroid nodules that are benign on FNA biopsy or are too small to biopsy should still be watched closely with ultrasound examination every 6 to 12 months.
Surgery for definitive diagnosis may still be recommended even for a nodule that is benign on FNA biopsy if it continues to grow, or develops worrisome features on ultrasound over the course of follow-up.
Frequently asked questions
conditions We treat
- Thyroid nodules
- Cancer of the Thyroid
- Salivary Gland lumps
- Salivary Gland and/or Salivary Duct Stones
- Enlarged Cervical Lymph Nodes
- Cancers of the Head and Neck Region
- Nasopharyngeal Cancer (NPC)
- Lesions in the Mouth & Oral Cavity
- Hemi / Total Thyroidectomy
- Salivary gland removal (submandibular / parotid gland)
- Removal of salivary duct stones
- Excision of Cervical Lymph Nodes
- Excision of Mouth & Oral Cavity Lesions