Thyroid disorders

One in three adults in Germany develops a thyroid disease in the course of their life, with the frequency increasing with age.

Thyroid diseases can affect either the hormone production of the thyroid (overactivity and underactivity) or the size or tissue structure of the thyroid.

Below you will find further information on the most common diseases of the thyroid.

This is an enlargement of the thyroid gland, which is often caused by iodine deficiency. This iodine deficiency can occur either as an absolute iodine deficiency (= too little iodine intake from food) or as a relative iodine deficiency during phases of life with increased metabolic activity (e.g. puberty, pregnancy).
However, hereditary factors can also be responsible for the development of a goitre (struma).

An overactive thyroid (hyperthyroidism) can be caused either by so-called thyroid autonomy ("hot nodules" or disseminated autonomy) or by autoimmune diseases such as Graves' disease (Morbus Basedow) or Hashimoto's thyroiditis. Due to the increased level of thyroid hormone in the blood, metabolic activity increases, which can lead to cardiac arrhythmias, high blood pressure, weight loss, nervousness, diarrhoea, hair loss and inner restlessness.

In a hot nodule (this term comes from thyroid scintigraphy), cells within a thyroid nodule produce thyroid hormone without being subject to control by the brain (via the hormone TSH). These are therefore also referred to as autonomous cells or autonomous adenomas. If the cells producing hormone in an uncontrolled way are not arranged as a nodule but are distributed throughout the entire thyroid gland, this is called disseminated autonomy.

In hypothyroidism (underactive thyroid), the body does not have enough thyroid hormone available for the necessary metabolic activity. This results in a reduced metabolism with symptoms such as tiredness, lack of drive, loss of appetite, constipation and weight gain.

Possible causes are either congenital hypothyroidism or hypothyroidism following autoimmune disease.

The term "cold thyroid nodule" comes from thyroid scintigraphy. It means that a thyroid nodule (diagnosed, for example, by ultrasound) does not produce any hormone. In the vast majority of cases, this is a benign nodule. Only in 2-3 % of cases can a malignant thyroid tumour be hidden behind a cold thyroid nodule. In many cases, further information can be obtained by an ultrasound-guided fine-needle biopsy. Unfortunately, even extensive diagnostics cannot always rule out that a malignant tumour is hidden behind a cold thyroid nodule. For this reason, interdisciplinary cooperation and extensive experience in deciding on therapy are essential, particularly in the case of cold thyroid nodules.

Graves’ disease is an autoimmune disease. The body mistakenly classifies its own thyroid cells as foreign cells, so that it produces defence cells (antibodies) which stimulate the thyroid gland. In addition, protruding eyeballs may occur. For the diagnosis of
Graves’ disease, the prerequisites are, in addition to the determination of antibodies (TRAb) in the blood, the ultrasound image, the scintigram and the detection of hyperthyroidism.

Hashimoto's thyroiditis is an autoimmune disease in which antibodies destroy the thyroid gland and the dead tissue is broken down by white blood cells. As a rule, certain antibodies against the thyroid can be detected in the blood (TPO antibody titre; TG antibody titre).

Malignant thyroid tumours are divided into differentiated tumours, i.e. tumours that still resemble healthy thyroid cells and can also take up iodine, and undifferentiated, i.e. uncontrolled-growing, tumours.

Among the differentiated malignant thyroid tumours, a distinction is made between papillary and follicular carcinomas.

Papillary thyroid carcinoma is the most common differentiated malignant tumour of the thyroid. If it is treated promptly and correctly, it has a very good prognosis. Above a certain tumour size, papillary thyroid carcinoma is treated by complete removal of the thyroid together with removal of the regional lymph nodes. In selected cases, clearance of the lymph nodes along the major blood vessels of the neck may also be necessary. The operation is followed by radioiodine therapy.

If small papillary carcinomas are discovered incidentally under the microscope in the course of thyroid surgery, in the vast majority of cases neither further surgery nor radioiodine therapy is required.

Follicular thyroid carcinoma is also one of the differentiated malignant thyroid tumours. With correct treatment and timely detection, follicular thyroid carcinoma also has a good to very good prognosis. It is treated by complete removal of the thyroid; as a rule, removal of the lymph nodes is not necessary. This is followed by radioiodine therapy.

A follicular carcinoma can only be confirmed by microscopic examination of a removed thyroid nodule. In contrast to papillary thyroid carcinoma, diagnosis by fine-needle aspiration is not possible. Likewise, examining the removed thyroid nodule during the operation is not useful in follicular carcinoma. For this reason, if a follicular carcinoma is diagnosed after thyroid surgery, a further operation to remove the entire thyroid may be necessary.

Undifferentiated thyroid carcinoma:
In undifferentiated thyroid carcinoma, the tumour cells no longer bear any resemblance to the original thyroid cells. Radioiodine therapy is not possible; chemotherapy is emerging as a new treatment option. Any treatment should be carried out in close consultation with surgeons, radiotherapists and oncologists.

Medullary thyroid carcinoma:
Medullary thyroid carcinoma (also called "C-cell carcinoma") does not arise from the actual thyroid cells but from so-called parafollicular, calcitonin-producing cells (so-called C cells). Medullary carcinoma occurs in families (approx. 15 %) or sporadically (approx. 85 %). The most sensitive tumour marker of medullary carcinoma is calcitonin, which is produced by the C cells. The treatment of choice is complete surgical removal. Radioiodine therapy is not possible.