An autonomous adenoma of the thyroid gland is a benign node (=adenoma) consisting of thyroid tissue that produces uncontrolled (=autonomous) thyroid hormones. Due to the excessive production of thyroid hormones, patients therefore often suffer from hyperthyroidism. The following text explains what the causes of such an autonomous adenoma can be and how it can be treated.
Causes of an autonomic adenoma
There are two main causes for the development of an autonomous adenoma: iodine deficiency and genetic factors. The thyroid gland depends on iodine as a building block for the production of its hormones. If there is a nutritional deficiency of iodine, the thyroid gland cannot produce enough hormones.
This upsets the entire regulatory cycle. The result is that the thyroid gland is stimulated by our brain to produce more hormones. As a result, nodes of new thyroid cells grow, which then produce an excessive amount of hormones with a better iodine supply – the result is hyperthyroidism.
Even though the iodine supply in Germany has improved significantly in recent decades, it remains one of the most common causes of autonomic adenoma. Genetic factors can also lead to the formation of thyroid nodes that cannot be controlled by the body’s own regulatory system. Consequently, the thyroid gland produces too much thyroid hormone. If there is a genetic cause behind an autonomous adenoma, several members of a family are often affected, but the symptoms can vary greatly. An endocrinologist can help determine the cause.
The thyroid disease Hashimoto Thyroiditis is a chronic inflammation of the thyroid gland caused by a misdirected reaction of our body’s immune system. Here our defence cells attack the body’s own thyroid tissue by mistake. In this context one also speaks of an autoimmune disease.
Hashimoto’s thyroiditis can also lead to an overactive thyroid gland in the meantime. In this case, however, no autonomic nodes are formed in the thyroid gland. In addition, the condition of hyperfunction is only temporary. Most patients with Hashimoto’s disease suffer from hypothyroidism in the course of the disease because so much thyroid tissue has been destroyed. Thus an autonomic adenoma can be easily distinguished from Hashimoto’s thyroiditis.
Diagnosis of an autonomic adenoma
The first suspicion of an autonomic adenoma is often raised clinically, which means that the doctor can form an initial impression based on typical symptoms (such as sweating, palpitations, lumps in the throat). In some cases, the autonomous adenoma can be palpated from the outside of the thyroid gland – but this is by no means common, as even very small nodules can often lead to severe symptoms. Blood is now often taken for further diagnosis.
Here the important thyroid gland values can be determined. A typical constellation in the case of hyperthyroidism in an autonomous adenoma would be elevated thyroid hormones (so-called fT3 and fT4) with a lowered regulatory hormone that is produced in the brain (so-called TSH). In the following, the node can be imaged with an ultrasound of the thyroid gland. In order to differentiate between an autonomous adenoma or Graves’ disease, a disease which is also associated with hyperthyroidism, a thyroid scintigraphy may be necessary. This is a radiological examination that identifies highly active thyroid tissue and can thus indirectly visualise the node.