What is a thyroid nodule?
Thyroid nodules are small or large lumps in the thyroid tissue that may form inside the thyroid. These nodules can form alone or in groups and are usually detected in imaging tests such as ultrasound or thyroid scan.
How many categories are thyroid nodules divided into?
Thyroid nodules are divided into different categories based on different characteristics, including tissue type, shape and structure, and ultrasound characteristics. Generally, thyroid nodules are divided into two main categories:
Benign nodules:
These types of nodules are usually non-cancerous and harmless. Most nodules in the thyroid are of this category and in large numbers. Approximately 90% of thyroid nodules are of this type. They often do not require immediate treatment, but should be evaluated by a doctor based on their size and other characteristics. Most people have at least one thyroid nodule during their lifetime.
Malignant nodules:
These types of nodules are rarer, but they may indicate thyroid cancer, and due to the risk of being cancerous, they are carefully examined by a doctor. Some people who have a family history of thyroid cancer or have been diagnosed as high risk or diagnosed with other thyroid diseases are at higher risk.
Other categories that are proposed for thyroid nodules are:
Suspicious nodules (Indeterminate Nodules):
Some nodules, especially in ultrasound, may have characteristics that require more accurate diagnosis. These nodules are classified as “suspicious” and may require further testing.
Non-Functioning or Low-Risk Thyroid Cancer:
These types of nodules are known as a relatively low-risk form of thyroid cancer. This type of cancer usually has chondrogenic growth and has less ability to produce thyroid hormones.
To accurately diagnose thyroid nodules and determine their type, a combination of thyroid scan, ultrasound, blood tests, and, if necessary, thyroid biopsy is often needed. Also, treatment decisions are made depending on the type of nodule and patient characteristics, such as size and cancer risks. Some thyroid nodules may require further investigation because of their large size, unusual appearance, or other symptoms. In this case, the doctor usually uses ultrasound, thyroid scan, blood tests and, in necessary cases, thyroid biopsy to determine a more accurate diagnosis and the appropriate treatment plan.
What is the cause of thyroid nodule?
The development of thyroid nodules may occur due to various factors, but exactly why a thyroid nodule develops is still not fully understood. Some of the factors that may play a role in the development of thyroid nodules are:
Genetic factors:
having a family history of thyroid nodule can increase the probability of developing it in people. If your parents or children have thyroid nodules, you may be more susceptible.
Environmental factors:
Environmental factors such as nutrition, exposure to certain chemicals, and X-ray or gamma radiation may play a role in the development of thyroid nodules. For example, thyroid nodules are more likely to develop in iodine-deficient areas.
Imbalanced thyroid hormones:
Failure to produce thyroid hormones or excessive use of thyroid medications can lead to thyroid nodules.
Thyroid inflammation or infection:
Thyroid inflammation or related infections may cause nodules to form.
Abnormal proteins in the thyroid:
Research has shown that the presence of abnormal proteins in the thyroid tissue may cause the formation of thyroid nodules.
If you think you have a nodule in your thyroid area, it is better to see a thyroid specialist doctor so that the necessary examinations can be done and, if necessary, the appropriate treatment can be determined, and do not self-medicate and do not diagnose the nodule.
What are the symptoms of each thyroid nodule?
Symptoms associated with thyroid nodules may vary according to the type of nodule and its characteristics. In many cases, these symptoms are unknown or caused by the size and location of the nodules. But in some cases, the following signs and symptoms may be observed for thyroid nodules:
Benign nodules:
Most of these nodules are found randomly in imaging and do not have specific symptoms.
In some cases, the enlarged nodule may press on the surrounding tissues and cause symptoms such as stiffness or swelling in the thyroid area.
Malignant nodules:
Most malignant nodules grow without specific symptoms at first. Over time, they may cause an increase in the size of the thyroid, which causes pressure on the surrounding tissues and the appearance of a gap or swelling in the thyroid area. In more advanced cases, symptoms such as fatigue, unexplained weight loss, stiffness or lumps in the neck area, angina (chest pain) and even shortness of breath may develop.
Suspicious nodules:
These nodules may not have any specific symptoms. If suspicious nodules are detected by ultrasound or other tests, a thyroid biopsy is usually done to determine their type.
Inactive nodules or mild thyroid cancer:
In most cases, these types of nodules are asymptomatic and are detected incidentally on imaging. In some cases, they may cause an enlarged thyroid and pressure on surrounding tissues, leading to swelling and pressure in the thyroid area.
However, if you feel that you have thyroid nodules or detect changes in the thyroid area, it is better to see a thyroid specialist for an accurate diagnosis and examination.
How are each thyroid nodule diagnosed?
Diagnosis of thyroid nodules may be done through a series of tests and diagnostic methods. A combination of these tests and examinations will help the doctor determine the type of nodule, whether it is benign or malignant, and whether it needs treatment or not. Below are several common methods for diagnosing thyroid nodules:
Ultrasound:
This method allows for the precise observation of nodules and the measurement of their dimensions. Ultrasound can also evaluate the appearance of nodules, such as firmness, swelling, cysts, or the presence of calcification (a coating of calcium crystals).
Blood tests:
Blood tests can measure thyroid hormone levels and other related parameters. These tests give your doctor information about your thyroid function.
Thyroid Function Tests:
Tests such as TSH, T3, and T4 levels in the blood can provide information that is useful in diagnosing thyroid status and function.
Thyroid Scan:
This test takes pictures of the thyroid and detects active and inactive nodules using oral or injected radiopaque substances.
Thyroid FNA:
In this procedure, a small sample of thyroid tissue is removed using a needle or small surgery to determine the type of nodule. This method is especially used for suspicious or malignant nodules.
Molecular Testing:
These tests use the analysis of genes or molecular markers to detect malignant nodules.
To make a more accurate diagnosis and determine the type of thyroid nodule, your doctor may order several tests and combine the results. This process helps the doctor to determine the right treatment plan for you.
What is the treatment for thyroid nodules?
The ways of treating thyroid nodules are different depending on the type of nodule and its characteristics. In most cases, benign nodules without significant symptoms or complications are harmless and do not require treatment on their own. But in certain cases, treatment may be necessary. In the case of malignant nodules, it also requires serious and specialist treatment. In the following, different treatment methods for thyroid nodules are explained:
Drug treatment:
In some cases, benign thyroid nodules that have thyroid activity (hyperthyroidism) may be controlled by taking antithyroid drugs that reduce the production of thyroid hormones. Medicines may be used in malignant nodules to control thyroid activity before surgery or radiation therapy.
Surgery (Thyroidectomy):
In cases of malignant or large thyroid nodules that have caused complications, surgery is performed to remove suspicious parts or the entire thyroid (thyroidectomy). This surgery can provide a more accurate diagnosis and treatment of the nodule itself.
Radioactive Iodine Therapy:
This method is used to treat malignant or active thyroid (hyperthyroid) nodules. By injecting a small dose of radioactive iodine, the tissues of the nodules are destroyed.
You should consult a thyroid specialist to determine the best treatment options. Note that any treatment decisions should be made based on the type of nodule, your medical history, and your health status.
References
Patient education: Thyroid nodules (Beyond the Basics) – UpToDate
Evaluation of a thyroid nodule – PMC (nih.gov)
pennmedicine.org/for-patients-and-visitors/patient-information/conditions-treated-a-to-z/thyroid-nodules
Automatic Recognition and Classification System of Thyroid Nodules in CT Images Based on CNN (hindawi.com)
Thyroid Nodules: Causes, Symptoms & Treatment (clevelandclinic.org)
