There are two groups of diseases of the thyroid gland:

1. The disturbance in the functions of the thyroid gland

a. Decreasing the thyroid hormone secretion – hypothyroidism

b. Increasing secretion of the thyroid hormone – hyperthyroidism (toxic goiter)

The symptoms that can be related to the hypothyroidism are fatigue, weight gain, loss in the hair and dry on the skin. The symptoms depending on the hyperthyroidism (toxic goiter) are palpitations, restlessness, trembling in the hands, sweating, and weight loss despite the good appetite. Both the hypothyroidism and symptoms of the hyperthyroidism can occur with many other reasons. In the presence of these symptoms, the non-thyroid causes should be sought in a patient whose blood thyroid hormone level is normal in the laboratory examination.

2. The structural diseases of the thyroid gland

The enlargement of the thyroid gland is called as goiter. The growth can occur throughout the thyroid, without nodules (diffuse goiter) inside of it or the nodules can form. A nodule means a mass that takes up space inside the thyroid gland. While there can be structures (colloidal nodules) where only the thyroid hormone is ponded, the thyroid tumors also occur as nodules. The colloidal (depending on the thyroid hormone ponding) nodules are very common in the adult population in Turkey. These nodules are very large and do not require treatment unless they cause difficulty in breathing or swallowing.

The thyroiditis

• Refers to some inflammatory diseases of the thyroid gland.

• Are infectious thyroiditis caused by microorganisms forming very few of them.

• Are more common encountered Hashimoto's thyroiditis, which are of autoimmune origin (showing reaction of the body against its own cells for an unknown reason). 

• The thyroid gland functions show variation widely. Initially, there can be a temporary period of hyperthyroidism, but in the period progressing depending on the destruction of the thyroid follicle cells, the thyroid functions return to their normal conditions and even the hypothyroidism can develop in the long term.

• If necessary, with the drug treatment, the level of the thyroid hormone in the blood is provided normal.

• There is no need for surgical treatment of the thyroiditis; however, especially the patients with Hashimoto's thyroiditis should be followed carefully.

The thyroid cancers

• The thyroid cancers are cancers of which rate of incidence increases most rapidly in our country. Its rate of incidence increases in both genders, especially in the young adulthood. Approximately 95% of the thyroid cancers in our country are the well-differentiated tumors originating from the follicular cells (which have not lost the basic features of the thyroid cell). The papillary, follicular and Hürthle cell cancers are included in this group. The medullary thyroid cancer constitutes a very small portion of the thyroid cancers. On the other hand, the anaplastic cancer is an extremely rare and often fatal type of the thyroid cancer.

• The thyroid cancers are the most common encountered papillary thyroid cancer. It is a very benign type of cancer. Especially in the young patients, if the right treatment is applied, its lethality is close to zero. 

• The treatment of the thyroid cancers is total thyroidectomy, which means removal of the entire thyroid gland, and removal of the necessary neck lymph nodes. In some patients,

The radioactive iodine treatment is required after the surgical treatment.

The thyroid cancers

• Examination

• Thyroid function tests (free T3, free T4 and TSH)

• Other laboratory investigations (antimicrosomal antibodies, thyroglobulin)

• Thyroid ultrasonography

• Thyroid gland scintigraphy

• Fine needle aspiration biopsy

The diagnosis

Most of the symptoms belonging to the thyroid gland diseases are undistinctive (non-specific) complaints. The patients with the large goiter, there are often symptoms such as difficulty in swallowing, difficulty in breathing, and a feeling of suffocation. Pain is not a common complaint. The voice change can be an important symptom. The information such as being a family history of the benign or malignant thyroid gland disease, exposuring to the radiation previously, living in an area where the goiter is common, or using the certain medications are also important.

The examination of the thyroid gland begins with the observation. The enlargement in the thyroid gland or some of the thyroid masses can be easily detected since they move with the way of swallowing. If the patient does not have a weak neck, the normal thyroid tissue cannot be palpable. The neck lymph nodes should also be evaluated on the examination.

The thyroid function tests should be checked in every patient. The laboratory examinations such as antithyroid antibodies (in the autoimmune diseases) and thyroglobulin levels (in the post-operative follow-up for the thyroid cancer) are needed in more specific cases. The thyroid ultrasonography is currently the most valuable method in the diagnosis and evaluation of the thyroid nodules. It allows us to evaluate the size and structure of the thyroid gland, if there is a nodule, whether it is solid or cystic, and its diameter. It is also used to follow up the nodule diameter and make guidance for the needle biopsy. The thyroid scintigraphy is helpful in the differential diagnosis in a very small portion of the thyroid diseases. The appearance of the nodule on the scintigraphy (warm or cold nodule) does not provide reliable information about the pathology found inside of it. With more development of the ultrasonography and fine needle aspiration cytology, the value of the scintigraphy in the evaluation of the nodules has been past its sell-by date.

The thyroid fine-needle aspiration biopsy is an examination having a high accuracy rate of 95% in the evaluation of the thyroid nodules. It should be done to the accompaniment of the ultrasonography. In the approach to the thyroid nodules, it is a very important step in making the decision for the follow-up or operation. The surgery is inevitable when the fine needle biopsy result is suspicious or malignant. If the unsatisfactory results are obtained, the process should be repeated after a while. If the result shows a benign nodule and there are no other problems such as compression symptoms, no treatment is required.

To correct the hypothyroidism, it is necessary to give the thyroid hormone externally. Since the thyroid hormone is already a substance produced by the human body; as is not a drug, it has no side effects when used in the right dose. If there is hyperthyroidism (toxic goiter), the thyroid functions of the patient are normalized with the antithyroid drugs. In a small part of the patients, the drug treatment is not sufficient and the surgical treatment or radioactive iodine treatment can be required.

The diseases of the thyroid gland that require the surgical treatment:

The thyroid tumors

• The cancers and adenomas (the benign tumors)

• The goiters that are large enough to cause the compression symptoms or that extend into the lungs (retrosternal)

The hyperthyroidism cases that cannot be treated with the medication (rarely) for the thyroid fine needle aspiration biopsy is an examination having a high accuracy rate of 95% in the evaluation of the thyroid nodules. It should be done to the accompaniment of the ultrasonography. In the approach to the thyroid nodules, it is a very important step in making the decision for the follow-up or operation. The surgery is inevitable when the fine needle biopsy result is suspicious or malignant. If the unsatisfactory results are obtained, the process should be repeated after a while. If the result shows a benign nodule and there are no other problems such as compression symptoms, no treatment is required.

The Surgical Treatment Technique:

The unilateral intervention will be sufficient only in the benign tumors in which there is pathology on one side of the thyroid gland and the other side is completely normal.

The basic principle is to remove all of the tissue on the side where the operation is performed.

The total thyroidectomy (removal of the entire thyroid gland) is performed in the surgical treatment of the thyroid gland cancers. When it is performed in the experienced hands, the complications depending on the operation (injury of the nerve that moves the vocal cords and formation of the hoarseness and possible damage on the parathyroid glands that play an important role in maintaining the body's calcium balance) are below 1%.

If a second surgical intervention is required in the same thyroid lobe, the risks belonging to this procedure are 8-10 times higher.

In the treatment of the thyroid cancers, the lymph nodes located on the side of the neck can also need to be removed.

If the entire thyroid gland is removed, it is necessary to give the thyroid hormone externally, which is necessary for the person to survive after the surgery. The thyroid hormone is not a drug, but it is a naturally occurring substance in the human body. When it is taken as a pill, it has no side effects when used in the right dose. After determining the appropriate dose for the patient, it can be used safely for life.

The use of neuromonitorization in the thyroid surgery (for the protection of the vocal cords)

One of the most feared complications in the thyroid surgery is hoarseness. Here it is, the neuromonitorization method helps us find these nerves that are closely related to the thyroid gland. By means of the neuromonitorization method, both the removal of the entire gland from whichever side of the thyroid gland is removed and the rate of damage to the nerves that move the vocal cords are minimized by providing the best results for the surgery. We routinely use the neuromonitorization method in our surgeries to prevent injury to the nerve that moves the vocal cords