What is a thyroid nodule?
Thyroid nodules come in several types — benign, malignant (cancerous) and cystic — and several may develop at once.
The incidence of thyroid nodules rises with age and is generally 3~4 times higher in women than in men.
Thyroid nodules are very common and are found in 30% of people who have an ultrasound as part of a health screening, but only 5-10% of these are malignant nodules, that is, thyroid cancer, which must be treated.
Causes
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A combination of various environmental and genetic factors
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Benign nodule / hyperplastic nodule: caused by iodine deficiency or environmental factors that induce thyroid cell proliferation
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Thyroiditis nodule: occurs when lymphocytic thyroiditis grows into a nodule
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Colloid nodule: caused by a buildup of colloid, a fluid produced by thyroid cells
Symptoms
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- Most thyroid nodules cause no symptoms, even when they are thyroid cancer.
- 2
- In some patients the nodule compresses surrounding tissue such as the esophagus or airway, causing symptoms such as a foreign body sensation, dysphagia and shortness of breath.
- 3
- A nodule may be felt or visible in the neck.
- 4
- A nodule may suddenly grow larger over a few days, accompanied by pain.
- 5
- If it grows over a few months, thyroid cancer may be suspected.
- 6
- Compression or invasion of the vocal cord nerve may cause hoarseness, coughing and similar symptoms.
Diagnostic methods
This test checks whether the nodule secretes hormones.
The size and characteristics of a nodule can be assessed accurately with thyroid ultrasound.
It is currently the most widely used test for thyroid nodules.
In this test, a fine needle is inserted directly into the thyroid nodule from outside to collect cells, and the type of nodule is determined from the appearance of the cells. If enough cells are not obtained at once, the test must be repeated.
Treatment
In thyroid radiofrequency ablation therapy (RFA), a fine probe (1 mm thick) is inserted into the nodule under real-time ultrasound guidance and radiofrequency heat of 100,000~500,000 Hz is delivered directly to necrotize the nodule. When radiofrequency energy at an appropriate level is applied, heat is generated in the tissue around the needle; this heat rises above the temperature at which the cells forming the nodule are denatured, so the cells are ultimately burned away.
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The procedure can be performed under local or sedation anesthesia alone, so there is no burden of general anesthesia.
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The procedure is short, only 5~20 minutes.
- 1
- The nodule is located with ultrasound, the skin is disinfected, and local anesthesia is given.
- 2
- Under ultrasound guidance, a radiofrequency needle is inserted into the center of the nodule.
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- Radiofrequency energy is applied to necrose the nodule cells.
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- Treatment time varies with the location and size of the nodule, but is usually within 20 minutes.
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- Follow-up ultrasound after the procedure confirms the treatment result for the nodule.
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- A needle is used without an incision, so no scar remains.
- 7
- Hospitalization is only short-term.
Post-treatment precautions
- Treatment results and duration may vary depending on individual symptoms.
- Temporary side effects may occur after treatment and vary with each individual's condition.