Main thyroid conditions

1. Hypothyroidism

Hypothyroidism occurs when the thyroid gland produces less hormone than the body needs, which slows down metabolism.

It is a common condition, especially in adult women, and in most cases it does not require surgical treatment.


Common causes

• Autoimmune disease (Hashimoto’s thyroiditis).
• Prior surgery or radioactive iodine treatment.
• Iodine deficiency.
• Medications (lithium, amiodarone).
• Congenital causes.

Symptoms

• Fatigue, drowsiness, mental slowness.
• Weight gain without changes in diet.
• Dry skin, hair loss, brittle nails.
• Cold intolerance.
• Constipation.
• Mood changes or depression.
• Menstrual irregularities or infertility in women.

Diagnosis

It is confirmed with elevated TSH and low free T4.

In some cases, thyroid autoantibodies are added to identify an autoimmune cause.


Treatment

Hypothyroidism does not require surgery. Treatment is based on hormone replacement with levothyroxine, with personalized dosing and monitoring by an endocrinologist. Appropriate management allows patients to live a completely normal life.

Dr. Yanzon works alongside a select group of endocrinologists specialized in the treatment of hypothyroidism, who support patients in achieving a stable and safe hormonal balance.

2. Hyperthyroidism

Hyperthyroidism occurs when the thyroid gland releases an excess of hormones, speeding up metabolism and causing symptoms such as nervousness, weight loss, palpitations, or insomnia.

In some cases, removal of the thyroid gland is necessary to cure hyperthyroidism, especially under the following circumstances:

• Large or compressive goiter.
• Toxic nodule or toxic adenoma functioning autonomously.
• Toxic multinodular goiter.
• Failure of, or intolerance to, medical therapy or radioactive iodine.
• When definitive control is desired—for example, in young women planning pregnancy or in patients with adverse effects from medications.

Thyroid surgery in hyperthyroidism

Thyroid surgery for hyperthyroidism can be a more challenging procedure, because these glands are often enlarged and more highly vascularized.

For this reason, it is essential to arrive at surgery with appropriate metabolic control, achieved through close collaboration between the surgeon and the endocrinologist. This helps minimize complications and ensure an optimal surgical outcome. In these procedures, the experience of the surgical team is critical to achieving the best results and maximum safety.

3. Thyroid nodules

Thyroid nodules are lumps or tumors that appear as small “balls” within the gland. They are a very common reason for endocrinology consultation. The majority are benign and do not require treatment, except when they are large (more than 4 cm), cause compressive symptoms, or show suspicious features on imaging studies.

Detection of a thyroid nodule requires additional tests to determine its nature.

Diagnosis and evaluation

• Thyroid ultrasound: determines the nodule’s size, number, shape, and content.
• Hormone tests: help assess whether the nodule affects thyroid function.
• Fine-needle aspiration (FNA): performed to analyze the nodule’s cells.

Not all nodules require FNA. It is especially recommended when:

• They measure more than 10 mm and have suspicious features.
• They show progressive growth.
• There is a family history of thyroid cancer.
• They are associated with suspicious neck lymph nodes.

Bethesda classification

The FNA result is reported using the Bethesda Classification, which guides the probability of malignancy and the recommended next steps:

Molecular testing

In some nodules with indeterminate results (Bethesda categories 3 and 4), molecular testing can be performed on the material obtained by FNA. These tests look for genetic alterations or mutations (such as BRAF, RAS, RET/PTC, or PAX8-PPARγ) that help determine malignancy risk and individualize the therapeutic decision, avoiding unnecessary surgery.

Treatment

Benign nodules are monitored periodically, except in cases where surgery may improve symptoms. Suspicious or malignant nodules, or benign ones that cause compression or discomfort, usually require surgical treatment. Surgery can confirm the diagnosis, relieve symptoms, and—when appropriate—cure the disease.

4. Thyroid cancer

Thyroid cancer is one of the most common malignant tumors. Fortunately, most cases have a very favorable prognosis with timely treatment.

In the vast majority of cases, thyroid cancer does not cause early symptoms. It is often discovered as an incidental finding during tests performed for other reasons, such as a neck vessel ultrasound.

When it becomes clinically apparent, it may present with:

• A firm or hard lump in the neck.
• Hoarseness or changes in the voice.
• Difficulty swallowing or breathing.
• Palpable lymph nodes.

Main types

There are different types of thyroid cancer. The most common are:

• Papillary carcinoma (≈85–90%): slow-growing and has an excellent prognosis with appropriate treatment.
• Follicular carcinoma (≈10%): generally favorable prognosis, with potential hematogenous spread.
• Medullary carcinoma: less common, arises from calcitonin-producing C cells; it may be associated with hereditary syndromes.
• Anaplastic carcinoma: very rare and aggressive.

Treatment

Treatment for thyroid cancer or suspected thyroid cancer includes—except in specific cases—surgery.

The extent of surgery depends on:

• Tumor type and size.
• Involvement of adjacent structures.
• Evidence or suspicion of affected lymph nodes.
• The patient’s preferences and overall health status.

In some patients with a presumed or possible diagnosis of differentiated thyroid carcinoma (papillary, follicular, or oncocytic cell), partial removal of the gland (lobectomy, hemithyroidectomy, or isthmusectomy) may be sufficient.

However, when there is a high likelihood of requiring radioactive iodine treatment, suspicious nodules in the other lobe, elevated anesthetic risk, or involved lymph nodes, complete removal of the gland is usually recommended.

The presence or suspicion of affected lymph nodes may indicate the need for a neck dissection, a procedure performed during the same surgery that requires additional operative time.

During surgery, the surgeon may require the collaboration of a pathologist in the operating room to perform intraoperative biopsies that allow the procedure to be adapted to the findings.

Thyroid surgery, with or without lymph node dissection, is complex due to the proximity of structures such as the trachea, the recurrent laryngeal nerves, the parathyroid glands, and the neck vessels.

International studies show that the best outcomes and lowest complication rates are achieved by high-volume surgeons (more than 40–50 cases per year).

Dr. Alejandro Yanzon performs more than 250 thyroid and parathyroid surgeries per year, making him one of the most experienced surgeons in Argentina and a regional reference in endocrine head and neck surgery.