Brief overview
- Definition: cell proliferation and/or cell enlargement in the thyroid gland. “Hot” (“warm”) nodes produce thyroid hormones, “cold” nodes do not.
- Symptoms: with larger nodes, problems swallowing, hoarseness, need to clear throat, general feeling of pressure in throat. Possibly pain when direct pressure is applied to the nodes. Indirect symptoms with hot nodes: Increased hormone production causes symptoms of hyperthyroidism.
- Causes: including benign tissue neoplasms in the thyroid gland (mainly autonomous adenoma – usually caused by iodine deficiency), cysts, rarely thyroid cancer or metastases.
- When to see a doctor? Whenever you notice nodular changes in the thyroid gland. Only the doctor can tell if treatment is necessary.
- Diagnosis: initial consultation, physical examination, ultrasound examination, scintigraphy for larger nodules, tissue sample (biopsy) for cold nodules.
- Prevention: Iodine-rich diet with plenty of sea fish and iodized table salt (not advisable in case of hyperthyroidism!). Pregnant women receive iodine tablets.
Thyroid nodules: Dangerous or not?
Most thyroid nodules are harmless. This is especially true for the so-called hot (hormone-producing) nodules. For cold (inactive) nodules, the risk of cancer is somewhat higher, at about four percent. Overall, less than one percent of all thyroid nodules are malignant.
Thyroid nodules: Definiton
Thyroid nodules develop when cells in individual areas of the hormone-producing organ proliferate and/or enlarge. Some nodules grow only to a limited extent, while others grow larger and larger. However, a thyroid nodule can also regress on its own.
Thyroid nodules: Frequency
Nodules in the thyroid gland are very common and become more frequent with increasing age. Overall, about 30 percent of adults show nodular changes in the hormone-producing gland, and in people over 65, the figure is even more than 50 percent.
Women are four times more likely to be affected by thyroid nodules than men.
In about ten percent of cases, thyroid nodules occur together with goiter.
Cold nodule, hot nodule
The differentiation of thyroid nodules into “hot” or “cold” has nothing to do with their temperature. Rather, it is about the activity of the nodules, i.e., whether or not they produce hormones.
- Hot nodes: If more hormones are produced in thyroid nodules than in the rest of the thyroid tissue, they are hot or warm nodules.
Where do the terms “hot” and “cold” come from?
The terms “hot” and “cold” for thyroid nodules come from scintigraphy – a nuclear medicine examination that can distinguish between the two types of thyroid nodules:
For the examination, the patient is injected with a liquid containing radioactive iodine, which enters the thyroid gland with the blood. A thyroid nodule that produces hormones needs a lot of iodine. The injected radioactive iodine therefore accumulates more in this tissue region. It decays, emitting radioactive rays that can be detected by a special camera – the affected area of the thyroid gland appears in the image as a yellow-red zone, i.e. in warm colors.
Thyroid nodules: Symptoms
Every thyroid nodule starts out small. Some nodules grow steadily until eventually they are so large that they cause problems swallowing, hoarseness, a need to clear the throat, or a general feeling of pressure in the throat.
Pressing directly on the nodule can hurt. Especially if the nodules develop as part of a struma nodosa, in which the thyroid gland is enlarged overall, painful symptoms can occur.
Normally, thyroid nodules grow very slowly and do not cause any discomfort for a long time. Therefore, they are usually discovered as incidental findings during routine examinations. However, a hot nodule can indirectly cause symptoms if it leads to increased hormone production. In that case, the same symptoms show up as in hyperthyroidism.
Thyroid nodules: Causes
- Benign tissue neoplasms in the thyroid gland (most commonly adenomas, less commonly lipomas, teratomas or hemangiomas).
- Cysts: These fluid-filled cavities often develop when thyroid tissue grows.
- Thyroid cancer: In Germany, it is estimated that less than one percent of all thyroid nodules are malignant – hot nodules almost never, cold nodules somewhat more often, but still rare overall.
- Metastases: Other cancers in the body can form daughter tumors in the thyroid. Such malignant thyroid nodules can develop, for example, in breast cancer, lung cancer, and colon cancer.
- Neck tumors: local tumors in the neck can grow into the thyroid gland.
Autonomous adenoma
If the thyroid gland receives too little iodine, it secretes growth stimulators. As a result, the thyroid cells multiply. In addition, when iodine is deficient, the pituitary gland releases a hormone that stimulates the production of thyroid hormones (thyroid-stimulating hormone, TSH). The increased TSH level causes the thyroid cells to enlarge – resulting in a benign thyroid tumor that produces thyroid hormones uncontrollably (autonomous adenoma).
Although the iodine supply of people in Germany has improved in recent years, thyroid nodules caused by iodine deficiency still occur frequently.
An autonomous adenoma can also result from certain genetic changes (mutations): The docking sites (receptors) of TSH may be altered due to a mutation in such a way that hormone production is cranked up further and further and uncontrolled.
Thyroid nodules: When do you need to see a doctor?
Thyroid nodules: What does the doctor do?
Especially in older patients, the general practitioner regularly checks the thyroid levels (TSH, T3/T4, calcitonin) in the blood. If he notices abnormalities, further examinations follow.
However, since thyroid nodules often do not cause any changes in the hormone balance, you should have your thyroid checked from time to time even if the blood values are normal.
Diagnosis
The first step in the diagnosis is to take your medical history (anamenes) during the initial consultation. The doctor will ask you various questions such as:
- When did you first notice the change in the thyroid area?
- Has the nodule grown since then?
- What complaints do you have (e.g., sleep disturbances, restlessness, etc.)?
It is especially important to differentiate malignant nodules from benign ones. Therefore, all factors that increase the risk of thyroid cancer must also be asked:
- Has thyroid cancer ever occurred within close relatives?
- Has the lump grown quickly?
- Do you suffer from hoarseness, cough or breathing problems?
This is followed by a physical examination. This involves the doctor palpating the thyroid gland. He pays particular attention to indications of malignant changes, such as a bumpy nodule surface or poor displaceability of the nodule when swallowing. The lymph nodes are also palpated for swelling.
The physical examination is followed by an ultrasound examination (sonography). An experienced physician can detect nodes as small as three millimeters. If the lump is larger than one centimeter or the blood values show a hormonal imbalance, a scintigraphy is advisable. This examination allows the physician to determine whether the nodule is hot (hormone-producing) or cold (inactive).
Treatment
With normal thyroid values and small, benign nodules, no treatment is initially necessary. However, one should have the thyroid gland examined regularly by a specialist. This is the only way to check whether the thyroid nodules are getting larger and whether the performance of the thyroid gland is changing.
If the doctor decides that treatment is necessary, three treatment options are available:
- Surgery: this involves removing either the entire thyroid gland (subtotal thyroidectomy), only one lobe of the thyroid gland (hemithyroidectomy), or only the thyroid nodule itself. The surgery can be performed open or laparoscopically (minimally invasive, with a reflection). Surgical intervention is useful if the thyroid nodule is suspected of being cancerous or if the thyroid gland is severely enlarged (goiter, goiter).
- Drug treatment: It is possible only for small, cold nodules. Patients receive thyroid hormones, usually in combination with iodine. The drugs inhibit the growth of the glandular tissue. However, if the nodule is larger and causes discomfort, this treatment is usually no longer useful.
Thyroid nodules: Prognosis
With proper treatment, benign thyroid nodules are usually curable. However, malignant thyroid tumors also usually have a good prognosis.
Thyroid nodules: What you can do yourself
A diet rich in iodine can prevent thyroid disease. Iodine is found, for example, in sea fish and iodized table salt. Since Germany is one of the iodine deficiency areas, you should make sure that you always get enough iodine in your diet. The easiest way to do this is to use iodized table salt.
If you follow these recommendations, you are already doing a lot to prevent thyroid nodules.
