It is the most common of all disorders of the thyroid gland.
It results from the genetic heterogeneity of the follicular cells and the apparent acquisition of new cellular qualities that become heritable.
Nodular goiter is often detected simply as a mass in the neck, but sometimes it is a gland that enlarges and produces pressure.
After a few decades, hyperthyroidism develops in a large proportion of the multinodular defect, often after excess iodine.
Multinodular goiter is simply a thyroid gland that usually enlarges and contains multiple thyroid nodules.
The nodules can be tiny, often only a few millimeters in size, or the nodules can be larger, perhaps several cm each.
There are usually two questions that need to be answered in patients with a multinodular goiter. The first question is usually:
Are all nodules benign?
The focus of this question depends on the clinical presentation, the associated risk factors, the size of the nodules, and whether the nodules work or do not work.
The diagnosis is based on a physical examination. The thyroid function test results are average or indicate subclinical or overt hyperthyroidism.
Imaging procedures help detect details such as distortion of the trachea and provide an estimate of volume before and after therapy.
4 to 17% of multinodular goiter cases meet the criteria for malignant change. However, most of these lesions are not lethal.
The treatment is controversial if a clinical and multinodular goiter is small and does not produce any symptoms.
The T4 given to reduce the gland or prevent further growth is effective in about one-third of patients.
The normal thyroid gland is a reasonably homogeneous structure, but nodules are often formed within its substance.
These nodules can be only the growth and fusion of localized colloidal follicles, more or less discrete adenomas, or cysts.
Nodules more significant than 1 cm can be detected clinically by palpation.
A careful examination reveals its presence in at least 4% of the general population. Nodules less than 1 cm in diameter that is not clinically detectable unless located on the gland’s surface are much more frequent.
The terms adenomatous goiter, nontoxic nodular goiter, and colloid nodular goiter are used interchangeably as descriptive terms when a multinodular goiter is found.
A goiter means enlarged thyroid. A goiter can be a simple goiter where the entire thyroid is more significant than usual or a multinodular goiter where there are multiple nodules.
Multinuclear goiters can be either a toxic multinodular goiter (that is, it produces too much thyroid hormone and causes hyperthyroidism) or nontoxic (that is, it does not have too much thyroid hormone).
It is not known what causes multinodular goiters in most cases. Still, it has been shown that iodine deficiency (very little iodine in the diet) and certain genetic factors lead to multinodular goiter.
Signs and symptoms.
Most multinodular goiters do not cause symptoms and are discovered on a routine physical examination or during a test done for another reason. Patients with a toxic multinodular goiter may have signs and symptoms of hyperthyroidism.
If the goiter is large enough, patients may present compression symptoms that include difficulty breathing (especially when lying down), food or pills that “get stuck” in the throat, and a feeling of suffocation in the neck.
These symptoms commonly occur if the goiter grows down into the chest, called a substernal goiter. If the goiter is large enough, it can be visible.
Nontoxic multinodular goiter symptoms may be non-existent.
If the goiter is very slow-growing and long-lasting, the patient may not notice the slow increase in size. However, some patients may complain of:
- a feeling of fullness in the neck.
- Choking sensation
- Difficulty swallowing large pills or thick foods
- The sense of pressure in the neck or worsening of snoring, especially with multinodular goiter that grows below the sternum.
A detailed medical history and physical examination should be made if a multinodular goiter is detected or suspected.
History is essential and includes the rapidity with which the thyroid grows, risk factors for thyroid cancer (family history of cancer and a history of radiotherapy in the neck or chest), family history of goiter, hoarseness, and symptoms hyperthyroidism.
Actual results of the physical examination include a goiter that can be felt, the growth down in the chest, and enlarged neck veins.
A thyroid ultrasound should be performed after a complete history and physical examination. There is no associated radiation. It is the best test to observe the thyroid and will allow the doctor to see the size of the thyroid and the specific characteristics of the nodule.
For example, size, number of nodules, if there are calcifications (calcium deposits), echotexture (that is, how bright or dark it looks), edges, shape, and whether it is solid or cystic (i.e.,, filled with liquid).
The appropriate treatment of a multinodular goiter depends on the size, the rapidity in which it is growing, the results of examinations, and the risk of cancer.
But also the symptoms of compression and if the goiter is large enough to be cosmetically unattractive.
In general, if the goiter is increasing, it grows steadily over time, is worrying for cancer, is causing compression symptoms, is growing underground, it must be eliminated (i.e., thyroidectomy).
The natural history of benign goiter is usually a slow growth of the nodules. Therefore, the observation can be safe.
The multinodular goiter is treated if there is suspicion of nodules that harbor cancer, the goiter proliferating, or the large goiter causing compression symptoms, such as hoarseness and difficulty swallowing or difficulty breathing.