Autonomous adenoma
An autonomous adenoma is a disease of the thyroid gland and describes a benign knot of autonomous thyroid tissue emanating from the glandular epithelium . Synonyms are hot knot , focal autonomy or Plummer's disease .
An autonomous adenoma also produces the thyroid hormones triiodothyronine (T3) and thyroxine (T4), but is no longer subject to normal regulation by the pituitary gland . The cells of the autonomic adenoma no longer produce thyroid hormones as needed, but regardless of the amount required. It shows up as a hot lump on thyroid scintigraphy .
Classification
| Classification according to ICD-10 | |
|---|---|
| E04.1 | Non-toxic solitary thyroid nodule |
| E04.2 | Non-toxic multi-nodular goiter |
| E05.1 | Hyperthyroidism with toxic solitary thyroid nodule |
| E05.2 | Hyperthyroidism with toxic multinodular goiter |
| ICD-10 online (WHO version 2019) | |
The thyroid autonomy is divided into three classes:
- A unifocal autonomy describes a solitary node (autonomous adenoma, frequency approx. 30 percent - constitutive activating mutations in the gene of the Gs-α protein or the thyrotropin receptor are considered to be causative).
- The multifocal autonomy designates a plurality of autonomous nodes that are distributed over the thyroid (two to three nodes about 50 percent; more than three other nodes 20 percent). This form is also the most common cause of hyperthyroidism in cats .
- The disseminated autonomy referred to in the strict sense, a close-knit distribution of autonomous cell areas heavy with Graves' disease should be distinguished (rare incidence greater than one percent of the autonomies).
- The simultaneous occurrence of Graves disease and thyroid autonomy is called Marine-Lenhart syndrome .
In addition, a distinction is made according to metabolic status, whether there is an overactive thyroid ( hyperthyroidism , toxic adenoma or “toxic node”) or a normal function ( euthyroidism , “non-toxic node”).
The proportion of autonomic adenomas in hyperthyroidism is between 15 and 50 percent, depending on the geographical area. A significant accumulation can be observed in iodine deficiency areas . In addition, autonomic adenomas are most noticeable from the age of 40 and the disease occurs about six times more often in women than in men.
Symptoms
Autonomous adenomas can occur without clinical symptoms . The TSH level is normal in these euthyroid adenomas . They should be checked regularly. If the TSH value is low, there is latent hyperthyroidism , which should be treated with medication.
Adenomas with hyperthyroidism are possible with and without patient complaints, but usually have elevated thyroid levels.
Possible symptoms can be:
- Nervousness, restlessness, insomnia
- Weight loss despite increased appetite
- Heat intolerance, increased sweating
- increased bowel movements, possibly with diarrhea
- Hair loss
- Cycle irregularities in women
- Muscle spasms
diagnosis
The diagnosis is made after a detailed anamnesis , laboratory diagnostics, sonography and scintigraphy . The medical history should ask about symptoms of hyperthyroidism and iodine exposure. The thyroid gland must be examined by palpation and the patient's eyes should be viewed (to rule out Graves' disease ). An increased resting heart rate is generally an indication of hyperthyroidism. TSH , T3 , T4 , and possibly thyroid antibodies (exclusion of autoimmune diseases ) provide information on laboratory values . A sonography searches for nodules. Thyroid scintigraphy should be performed from a nodule size of 1 cm . In this scintigraphy, the function of the thyroid tissue is shown by giving a small amount of radioactive technetium . The technetium is absorbed into the thyroid cells via the same mechanism as iodine ( sodium iodide symporter ).
Visibly and palpably enlarged thyroid with a lump in front of the windpipe (pretracheal).
In the thyroid scintigraphy with 99m Technetium four autonomous adenomas show.
In scintigraphy with 131 iodine in preparation for radioiodine therapy , the adenoma is the pretracheal leader.
therapy
Therapy is not necessary in symptom-free euthyroid patients. However, the thyroid values should be checked regularly - at least once a year. Patients should be made aware of the problems of iodine overload.
Therapy must be given in the event of latent or manifest hyperthyroidism. This can be done by means of an operation, medication, radioiodine therapy or, alternatively, a percutaneous alcohol injection . Drug treatment is usually the first stage of treatment. The autonomic thyroid is prevented from processing iodine absorbed by drugs such as thiamazole or propylthiouracil .
An operation is used, for example, in the case of a large goiter that causes mechanical problems, a cold lump that is present at the same time or after other forms of therapy have failed. This form of therapy has the advantage of quick and permanent help, but it also harbors all the dangers of an operation, including the possibility of injuring the vocal cord nerves and / or removing the parathyroid gland as well .
