A goiter is a pathological enlargement of the thyroid gland. Colloquially, a goiter is often referred to as a “goiter.” In most cases, it is so small that it cannot be seen or felt. However, it can also swell to the size of a tennis ball (or larger) or even grow even bigger. A goiter can also manifest as lumps on the thyroid gland. The word “goiter” is a Latin term that can be translated as “tumor” or “swelling of the gland in the neck.”
Goiter with a large, palpable nodule
Goiter is often classified based on its size. The normal volume of a thyroid lobe is approximately 5–15 ml, with a total volume of 15–25 ml. This volume can be easily determined using ultrasound.
Goiters are classified by stage based on their size as follows:
- Grade 0: visible only on ultrasound
- Grade I: Enlargement is palpable but not visible
- Grade II: Enlargement visible at close range during examination, but without symptoms
- Grade III: Enlargement visible from a distance (already visible upon entering the room) with signs of compression (shortness of breath, difficulty swallowing)
A special form is the so-called retrosternal goiter. In this case, the thyroid gland enlarges to extend behind and below the sternum. It can become quite large without being visible from the outside.
A nodular goiter refers to an enlargement of the thyroid gland accompanied by the formation of nodules. “Nodus” translates to “nodule.” These thyroid nodules are easily detectable on ultrasound. However, there is also a diffuse enlargement of the thyroid gland without nodules; this is referred to as a diffuse goiter.
A more precise differentiation of the nodules can be made based on their uptake of iodine and thus their hormonal activity, classifying them as “cold” or “hot” nodules. “Hot” means that there is pronounced metabolic activity, whereas “cold” nodules take up little or no iodine. The distinction between “cold” and “hot” is usually made using thyroid scintigraphy.
“Cold” nodules generally require further investigation, as they may mask a malignant condition.
There are various causes of a goiter. Very often, affected patients have an iodine deficiency. This trace element is needed to produce thyroid hormones. Since the body cannot produce iodine on its own, it must be obtained in sufficient quantities through the diet. For this reason, goiter is a condition that occurs particularly in areas with iodine deficiency. When iodine is lacking, the thyroid gland enlarges to compensate for this deficiency. As part of this process, the organ’s tissue releases growth factors that lead to cell proliferation.
If iodine deficiency persists over a long period, the thyroid hormones thyroxine (T4) and triiodothyronine (T3) cannot be produced in sufficient quantities. The less active T4 hormone is converted into the more active T3 hormone through the removal of an iodine atom. T4 is present in higher concentrations and thus serves as a storage form, whereas T3 is present in smaller quantities but in its active form. When too few thyroid hormones are produced, the pituitary gland stimulates the thyroid—and thus the production of T3 and T4—by releasing increased amounts of TSH (thyroid-stimulating hormone). As a result, the thyroid cells grow, leading to the development of a goiter.
Are there other causes of a goiter?
Although the aforementioned iodine deficiency is the most common cause of a goiter, other factors can also play a role. For example,
this can also contribute to the development of a goiter.
Among the best-known autoimmune diseases of the thyroid are Hashimoto’s thyroiditis, which leads to chronic inflammation, and Graves’ disease, which is often associated with an overactive thyroid.
However, not all goiters are the same. For example, patients may develop a goiter in which the thyroid gland still functions normally. Goiters are classified according to various criteria:
- Characteristics
- Function
- Size
A goiter does not necessarily cause symptoms. In many cases, those affected do not even realize they have developed a goiter. As a result, it is often not discovered until a routine examination. This is sometimes referred to as a “hidden goiter.” Nevertheless, patients with a goiter may complain of symptoms that indicate this condition. For example, a feeling of tightness in the throat may occur. As the goiter grows larger, this sensation may intensify, and patients often complain of feeling as if they have a lump in their throat.
If the thyroid gland swells, it can also press on the windpipe, making it difficult for the patient to breathe. This results in shortness of breath during physical exertion or when moving the head in certain ways. Furthermore, a larger goiter or one located in an unfavorable position can also cause problems with the vocal cords or difficulty swallowing.
In many cases, the goiter is not visible to the naked eye, so further tests are required. Careful palpation of the thyroid gland can sometimes reveal enlargement or nodules, even if the gland appears normal and not enlarged from the outside.
In addition, an ultrasound should be performed, as it often allows for clear visualization and measurement of the thyroid’s size. In most cases, this also makes it possible to determine whether the condition is simply an enlargement of the thyroid gland (diffuse goiter) or involves the formation of additional nodules (nodular goiter).
A blood test can also be helpful. In this test, the TSH level is specifically examined. If it is significantly elevated, this could indicate an iodine deficiency and, consequently, a goiter. Furthermore, a blood test can measure the thyroid hormone levels (T3 and T4) mentioned above.
A thyroid scan is also indicated if a goiter is suspected. For example, in the case of a nodular goiter, so-called “cold” nodules could be a sign of thyroid cancer. A scintigraphy can distinguish between “cold” (low-iodine-uptake) and “hot” (high-iodine-uptake) nodules. The test is performed by radiologists.
There are various ways to treat a goiter. The choice of treatment depends on the cause of the goiter:
- In cases of iodine deficiency, the patient can and should initially be given iodide. This can correct the iodine deficiency—the most common cause of a goiter—and restore normal thyroid function.
- In cases of an autoimmune disease or chronic inflammation, the administration of thyroid hormones is often necessary as well. These are available in tablet form, sometimes in combination with iodide. Examples include medications such as Thyronajod or L-thyroxine
- Surgery may also be the treatment of choice. This is particularly the case when there is a malignant lesion in the thyroid gland. However, even if, for example, breathing becomes difficult and the thyroid gland is pressing on the trachea, a partial or complete removal—partial resection or resection—may be necessary
Since a goiter is a chronic enlargement of the thyroid gland that often develops over many years, complete resolution of the goiter is rare or impossible. However, further enlargement can be prevented by taking appropriate measures, as described above.
After surgical removal of the enlarged thyroid gland, it may be necessary to take thyroid hormone replacement medication for the rest of one’s life. This depends, among other things, on the size of the remaining thyroid tissue and its hormonal activity following the surgery. Therefore, regular monitoring of thyroid hormone levels through laboratory tests is necessary. In addition, it is recommended to have the thyroid gland—or the remaining portions of the thyroid gland—regularly examined by a physician and monitored via ultrasound.
What is a goiter?
A goiter is a pathological enlargement of the thyroid gland. The term “goiter” describes a visible or palpable enlargement of the thyroid gland in the neck. A goiter can present as a diffuse goiter or a nodular goiter with lumps.
What causes a goiter?
The most common cause of a goiter is iodine deficiency. Other causes of a goiter include Graves’ disease, hyperthyroidism, hypothyroidism, or impaired hormone production by the thyroid gland. Cold nodules, cysts in the thyroid gland, or a malignant tumor can also cause an enlargement of the thyroid gland.
What symptoms can a goiter cause?
An enlarged goiter can cause local symptoms such as a feeling of pressure, shortness of breath, difficulty breathing, or trouble swallowing. If the goiter grows significantly, the enlarged thyroid gland may press on surrounding organs. However, some goiters remain symptom-free for a long time.
How is the diagnosis made?
Diagnostic tests include ultrasound, scintigraphy, and a nuclear medicine examination. In addition, thyroid hormones T3 and T4 as well as TSH are measured. In the case of thyroid nodules—diagnosis and treatment—tests are performed to determine whether the nodules are benign or malignant.
What treatment options are available for goiter?
Treatment for goiter depends on the cause and size of the enlarged thyroid gland. Options include medication involving thyroid hormones or iodine, radioiodine therapy, and surgery. The goal is to reduce the size of the goiter and correct hyperthyroidism or hypothyroidism.
