Indications
Papillary thyroid cancer often occurs as a microcarcinoma, i.e. as a tumor less than one centimeter in size. Therefore, it remains clinically silent at first and is not noticed by the patient. Even experienced physicians cannot feel such small structures, for example during a routine check-up.
Since papillary carcinomas spread primarily by lymphogenic means, lymph node metastases may develop during the course of the disease, which are more likely to appear as the primary tumor. Attention should be paid to hardened lymph nodes in the neck region, which are not easily displaced. Distant metastases are more likely to be found in follicular thyroid carcinoma, as this is a cancer that spreads through the bloodstream.
Thus, metastases can affect the skeleton and the lungs, the two most common sites of metastasis. Other symptoms of papillary and follicular tumors are hard, palpable nodules in the thyroid gland or an apparent enlargement of the same. In the later course of the disease, if not detected, infiltrations of the surrounding tissue – the muscles, trachea and esophagus – occur.
Nerves can also be damaged by the tumor. If the laryngeal recurrent nerve is affected, hoarseness occurs if one side is damaged and hoarseness and shortness of breath if both sides are affected. The reason for this is the function of the nerve: the innervation (nerve supply) of the inner laryngeal muscles, which move the vocal cords.
In addition to recurrent paresis (recurrent paralysis), Horner’s syndrome can occur, which is caused by damage to the sympathetic nerve-controlled eye muscles. This complex of symptoms includes miosis (pupil reduction), ptosis (lowering of the eyelid) and, depending on the scientific opinion, (pseudo-)enophthalmos (protrusion of the eye). Medullary thyroid carcinoma is also often discovered late, as it can initially develop without symptoms.
A conspicuous finding in an examination with subsequent biopsy of a lymph node or distant metastasis often leads to an initial diagnosis. If the tumor cannot be successfully treated or is not noticed, a relevant increase in the calcitonin level may occur. This hormone is produced by the C-cells and is released in increased amounts in the case of malignant degeneration.It lowers the blood level of calcium by increasing its excretion through the kidneys, decreasing its absorption in the intestines and reducing the activity of the cells that break down bone substance (osteoclasts).
Consequences of an increased calcitonin level can include flush (reddening of the skin due to increased blood circulation, see flush syndrome), diarrhea and dizziness. A slight lack of calcium (hypocalcemia) may also occur, which is manifested by increased excitability of the skeletal muscles – muscle twitching or cramps may occur. Due to the rapid development of anaplastic carcinoma, the disease manifests itself relatively quickly.
There is a unilateral swelling of the throat which is accompanied by difficulty swallowing and increasing hoarseness. A sudden swelling of the neck must always be examined as soon as possible, since other dangerous diseases (allergic reaction) can also be the cause. In rare cases the thyroid hormones can be influenced by malignant tumor diseases.
Both an underfunction, a reduction in hormone production, and an overfunction, an increased hormone production, can influence hair growth and its structure. The thyroid hormones have important tasks in controlling the growth and development of the human body. Due to an underfunction it can happen that hairs lose their thickness and diameter.
The density can also be lost – the hair appears dull and is brittle. Therefore they fall out more easily. This also happens in the case of an over-function, although here the growth can be accelerated first.
As a result, the hairs enter their resting phase more quickly – they do not become as long, are thinner and more brittle. Thyroid cancer can be treated with radioiodine therapy. This usually follows surgical removal of the thyroid gland, but is also used in cases of severe hyperthyroidism.
In radioiodine therapy, the patient is administered radioactive iodine. This is stored in the thyroid gland, which is responsible for the iodine balance in the body and needs the iodine to build up the hormones. The radioactive substance destroys the tissue from which it is absorbed.
This can result in a therapy-induced hypothyroidism, which can lead to a lack of drive and weight gain, but also to the hair loss described above. Often, the diagnosis of papillary or follicular thyroid carcinoma is made by removing minute amounts of tissue from the suspicious structures. These are then examined under the microscope in the laboratory and findings are made.
The blood values play a rather minor role in the diagnosis, as they are inconspicuous in most cases of disease and only rarely show increased thyroid hormone production. In some cases, the thyroglobulin (TG = carrier substance of the thyroid hormones in the blood), which is produced and stored in the thyroid cells, is elevated. It is normally present in small amounts in the blood – an increase indicates a thyroid problem.
Medullary thyroid carcinoma is also mainly detected by histological examination. Since the cancer consists of C-cells, a conspicuous blood test can be observed here. C-cells produce calcitonin, a hormone of calcium metabolism, which can be measured in the blood.
Due to the proliferation of the cells in the context of cancer, the calcitonin level in the blood increases several to a thousand times. At the same time, the tumor marker CEA (carcinoembryonic antigen) increases, which is elevated in the context of many different malignant tumor diseases. In the case of anaplastic thyroid carcinoma, only the clinical abnormality is groundbreaking. The thyroid hormones appear completely normal in the blood count and are therefore of no diagnostic help.
