Thyroid

The thyroid is a gland in the endocrine system located at the front and bottom of the neck, just below the Adam's apple. Its function is to produce thyroid hormone, which is responsible for the body's overall metabolism. Diseases that occur in the thyroid can affect its function (hypothyroidism, or decreased or increased function) or its form (thyroid nodules, goiter, cancer). In general, diseases related to function are treated by endocrinologists, while diseases related to form are managed by head and neck surgeons.

Thyroid nodules are a generic name given to any nodular formation that occurs in the gland, and they can be benign or malignant, single or multiple, and functioning or non-functioning. In general terms, most nodules are benign and non-functioning and correspond to a disease called goiter (also popularly known as “coto”). When these become functioning, they are called hyperfunctioning adenomas.

About thyroid cancer

Only a few are the first sign of thyroid cancer. Since it is impossible to determine whether a nodule falls into any of the above categories, all thyroid nodules measuring more than 1 cm should be evaluated with a fine needle aspiration biopsy (FNAB) to determine the course of action.

In Colombia, goiter is endemic (that is, it occurs frequently in many people without a clear triggering factor) and quite common in women over the age of 40. It used to be associated with low iodine intake. Currently, iodine intake is sufficient, and it is believed that goiter also depends on some family factors and others related to diet. Most goiters do not produce symptoms and are usually discovered during a routine examination or with the use of ultrasound. Most symptoms such as pain, burning in the throat, and voice changes are not usually related to goiter. Having a goiter does not necessarily indicate a functional disorder, so much so that goiter can exist with or without hypothyroidism.

Goiter only requires surgical treatment when:

a) It grows rapidly and causes symptoms such as difficulty breathing or swallowing. b) When it is large or growing toward the chest. c) When it is associated with increased gland function. d) When there is a strong suspicion of cancer.

Functioning thyroid adenomas are rare diseases. Most first manifest as hyperthyroidism (hyperactivity, irritability, profuse sweating, feeling hot when others feel cold, palpitations, fatigue, weight loss or inability to gain weight, increased appetite, diarrhea, menstrual disorders, hand tremors, and hair loss, among others). and then during the study it is discovered that it is a hyperfunctioning nodule. All patients with this diagnosis are treated with surgery.

Thyroid cancer is quite common in our environment and its incidence has been steadily increasing. Most cases occur in women between the ages of 30 and 60, with a history of radiation therapy to the neck (such as for breast cancer) and a history of goiter or family members with the disease. The most common symptom is the appearance of a rapidly growing lump in the neck. Occasionally, voice or swallowing changes may occur, but this is uncommon.

There are four types of thyroid cancer:

a) Papillary, which is the most common and benign. b) Follicular and a subtype of Hurthle cells, which is less common and slightly more aggressive than papillary. 
c) Medullary, which has a strong genetic component and is quite aggressive. d) Anaplastic, which is a very aggressive tumor that usually appears on goiters that have been developing for a long time.

Most cases are diagnosed in the early stages of the disease (still within the gland), which allows for cure rates of over 90%.

All patients with this diagnosis are treated with surgery (total thyroidectomy with or without cervical lymph node dissection) and some may require the administration of a therapeutic dose of radioactive iodine, which involves the use of radioactive iodine to eliminate all traces of the disease.