Thyroid nodule, nodular goiter, cold nodule, (warm) hot nodule

Every node in the thyroid gland is to be rated as pathological. The prevalence is high in our part of the world and amounts to 20-30% of adults with a lump of >1cm. The numbers are even higher for older people and those with iodine deficiency.

A high percentage of the nodes are cold and the likelihood of degeneration is described in the literature as between 3-10%. Some of the lumps can be palpable and, depending on their location and size, can cause various symptoms: feeling of pressure, difficulty swallowing, pain, or they can be completely asymtomatic. In addition to the morphological properties such as size, position and echo behavior, it is also important to record the storage behavior with a scintigraphy using ultrasound.

According to the storage behavior, a distinction is made between cold (hypofunctional) and hot nodes, with hot nodes producing hormone independently without being subject to the control cycle and cold nodes no thyroid hormone production, but an increased risk of degeneration (follicular Neoplasia). Therefore, cold nodules are most important from a medical point of view and require close inspection, a fine needle puncture and, if the size is >1 cm, especially if there are additional malignancy criteria, surgical treatment.

Some of the nodules have a completely normal storage behavior, do not differ from the rest of the thyroid in terms of scintigraphy and are of little pathological relevance. In this case, only an ultrasound check is to be carried out at regular intervals.

If, however, growth occurs with normal thyroid values ​​or with adequate hormone substitution, especially with additional thyroid-related complaints, therapy is recommended.

Therapy options

Normally storing node:
Regular follow-up checks with ultrasound, possibly scintigraphy, thyroid values ​​such as TSH, fT3 and fT4, and rarely tumor markers (TG and calcitonin) are recommended. If the metabolism is normal, and in any case if the metabolism is hypothyroid, hormone substitution should be initiated, especially in the case of corresponding complaints. Surgery is only indicated if the patient has grown in height, has other malignancy criteria or has other symptoms.

Cold knot:
If there is a suspicious palpation finding or if a routine ultrasound of the thyroid gland shows, which can be solid or cystic, a scintigraphy is always connected to determine the behavior more precisely. If the scintigram shows a less or non-storing area (hypofunctional) in correlation with the ultrasound, one speaks of a cold thyroid nodule or a so-called follicular neoplasia. Cold nodules have a significantly increased risk of malignant degeneration. In addition to the thyroid values ​​TSH, fT3 and fT4, calcitonin and possibly CEA should be taken as tumor markers.

Assured risk factors for the m ailgne degeneration of a cold lump:

  • Irradiation of the thyroid bed that took place
  • History of a family history of medullary thyroid cancer, multiple endocrine neoplasia or familial colon polyposis, …
  • Size of the knot: knots under 1cm have a low tendency to degenerate, over 1cm a significantly higher tendency
  • Nodes of the same size have a higher tendency to degenerate in young patients
  • The degeneracy tendency is slightly higher in women and is 1.75:1

Puncture cytology using fine needle aspiration of cold nodules, especially in the case of follicular neoplasia, often shows unusable results and, under optimized conditions, benign findings in 69%, suspicious findings in 10% and malignant findings in 4%. However, a benign cytological result does not rule out a malignancy and can produce false negative results in up to 28%. Nevertheless, the FNA is a valuable tool to further characterize cold nodules.

Depending on the risk profile, cold nodules (>1cm) are almost always an indication for surgery due to the increased risk of degeneration.

Hot knot: is not subject to the control loop and produces hormones independently. The rest of the thyroid tries to compensate for this "going it alone" by producing less thyroid hormone and in total an adequate amount of thyroid hormone is available for the body. At the latest, when there is decompensation and too much thyroid hormone is produced overall, in other words when there is an overactive thyroid, therapy with radioiodine ablation or surgery is indicated.

In the vast majority of cases, there is no malignant degeneration of hot nodes. The hot knot behaves differently in children. Malignant degeneration can occur here in up to 18%.