In recent years, along with the suspicion of excessive iodized salt, people have become more and more concerned about thyroid disorders, and once they find out they have thyroid nodules, they worry that they are cancerous. Experts point out that people have great misunderstanding about thyroid nodules.
In fact, thyroid nodules have a high incidence in the population, but the percentage of malignant nodules is low, accounting for only about 5%, and more than 95% of people have benign nodules. Therefore, there is no need to panic when a thyroid nodule is detected, and not everything should be done, but you need to be wary of over-treatment.
The words “microcalcification, hypoechoic” should be examined further
To determine the benignity or malignancy of a nodule, a combination of factors is needed. First of all, we should look at the medical history and manifestations. If the nodule has been exposed to radiation in childhood, if someone in the family has thyroid cancer, if the nodule is rapidly growing, hard and fixed, and if it is accompanied by persistent hoarseness, dysphonia and dysphagia, we should be alert to the possible malignancy of the nodule.
Secondly, it is important to look at the ultrasound examination results. When you get the ultrasound report, many people will be shocked to see “thyroid nodule” written on it. Many people are surprised when they see “thyroid nodules” written on the report, followed by a long list of medical terms such as “microcalcification, coarse calcification, spongy pattern, hypoechogenicity”, which are confusing to understand.
There are some key words in the ultrasound report that can help patients to understand whether the nodule is benign or malignant. If the ultrasound result states “hyperechoic, coarse calcification (except for medullary thyroid carcinoma), abundant blood flow around the nodule (under normal thyrotropin), spongy pattern, and comet tail sign behind the nodule”, then it often indicates a benign nodule and there is no need to panic.
If there are words like “microcalcifications, hypoechoic, nodule with abundant internal blood supply and disorganized distribution, irregular border, incomplete surrounding halo, anterior-posterior diameter greater than left-right diameter in cross-section”, it means the possibility of thyroid cancer is higher and further examination is needed.
Proper treatment
If thyroid cancer is suspected, “characterization” by fine needle aspiration is more accurate
It is not uncommon for patients who are suspected of having thyroid cancer to undergo surgery without close examination and end up with a benign lesion. The most reliable way to determine whether a nodule is malignant or benign, and whether surgery is needed, is to perform a fine or coarse needle aspiration of the nodule to obtain a small amount of tissue for pathological examination and diagnosis.
Patients are often resistant when they hear that a puncture is required. “Fine needle aspiration puncture is commonly performed with a 25-gauge needle, is safe and easy to perform, and is one of the most commonly used methods that can be performed with or without local anesthesia.” Fine needle aspiration is not very risky, and only a very small number of patients experience local swelling and pain or bleeding or infection.
Some patients with mixed nodules or those located in the posterior thyroid lobes require ultrasound-guided puncture to avoid misdiagnosis. Patients should also undergo ultrasound-guided fine-needle aspiration biopsy when they have a history of high-risk thyroid malignancy or when ultrasound suggests signs of suspected malignancy, as long as the nodule is larger than five millimeters in diameter.
High-risk history of thyroid cancer includes a first-degree relative with thyroid cancer, a history of external radiation treatment as a child, a history of radiation exposure as a child or adolescent, and thyroid cancer detected during a partial thyroidectomy in the past.
However, there are four cases in which a puncture biopsy is not necessary. The first is a “hot nodule” confirmed by thyroid nuclide imaging, and the second is a purely cystic nodule suggested by ultrasound. The third is a nodule that is highly suspected of being malignant based on ultrasound images. Fourth, the nodule is less than one centimeter in diameter, and there is no sign of malignancy on ultrasound.
Correction of misconceptions
Blind removal of benign nodules may result in hypothyroidism instead
Malignant nodules should be surgically removed as soon as possible, and after surgery, thyroxine should be taken for life for suppressive treatment. In the case of benign nodules, it may not always be necessary to get rid of everything. Some patients blindly remove benign nodules because they are “afraid of cancer” and end up with hypothyroidism (i.e., “hypothyroidism”).
If a benign nodule has normal thyroid function, regular observation is all that is needed and surgery is not necessary. However, if a benign nodule is combined with hyperthyroidism, as evidenced by elevated triiodothyronine (T3) and thyroxine (T4) levels and decreased thyrotropin (TSH), treatment with medication or isotope 131I is required. If hypothyroidism develops after nodal surgery, long-term replacement therapy with levothyroxine (L-T4) is required.
Special Reminder
Benign thyroid nodules can be followed up every six months to a year
If a nodule is found to be suspicious in character but the patient resists puncture, it can be reviewed at regular intervals (3 to 6 months). For thyroid nodules that are diagnosed as benign, follow-up can be done every six months to a year. Patients with benign nodules should pay attention to self-observation and seek immediate medical attention at the first sign of hoarseness, difficulty in breathing, difficulty in swallowing, fixation of nodules, and enlargement of lymph nodes in the neck.
Doctors remind that there are some tests that do not need to be done in the process of confirming and reviewing the diagnosis. People often ask for CT, MRI and whole-body PET-CT with a medical report that says “thyroid nodule”, but they are actually no better than ultrasound in terms of sensitivity and specificity.
Patients with benign nodules need to have their thyroid ultrasound reviewed during follow-up visits to the hospital, and thyroid autoantibodies and thyroglobulin quantification may be of some help in determining the cause of the nodule, but these two tests are of little value in identifying benign and malignant nodules.