substernal goiter

A substernal goiter, also known as retrosternal goiter, is a condition where the thyroid gland becomes abnormally enlarged and extends into the chest cavity below the level of the sternum (breastbone). This can occur when the thyroid gland grows downward towards the chest cavity instead of outward in the neck region.

Characteristics:

• The thyroid gland has descended below the plane of the thoracic inlet or has more than 50% of its volume extending into the chest.
• Substernal goiters are biologically a type of nodular goiter and a variant of nodular goiter.
• They can be located in various parts of the mediastinum, with most being in the anterolateral or anterior mediastinum.

Incidence:

• The incidence of substernal goiter in thyroidectomy procedures varies between 2% and 19% due to the lack of a clear consensus on the definition of this pathology.
• Up to 10% of substernal goiters are located in the posterior mediastinum, with 90% of those being right-sided.

Causes:

• Iodine deficiency is the most common cause of goiter worldwide, which can lead to the development of a substernal goiter.
• Other causes may include genetic predisposition, thyroiditis, or other underlying medical conditions.

Symptoms:

• Symptoms related to the size of the goiter may include a sense of a lump in the throat, difficulty swallowing, difficulty breathing, and even respiratory distress in severe cases.
• Compression of the trachea and/or esophagus can lead to symptoms such as dyspnea (difficulty breathing), choking sensation, and other respiratory issues.

Treatment:

• Substernal goiter is typically treated surgically through a substernal thyroidectomy, which involves removing the affected portion of the thyroid gland.
• In some cases, medical management may be considered, especially if the patient has underlying conditions that need to be addressed before surgery.

References:

[1] - Definition of substernal goiter as one that has descended below the plane of the thoracic inlet or has more than 50% of its volume extending into the chest. (Source: [9]) [2] - Incidence of substernal goiter in thyroidectomy procedures varies between 2% and 19%. (Source: [11]) [3] - Up to 10% of substernal goiters are located in the posterior mediastinum, with 90% of those being right-sided. (Source: [12])

Common Signs and Symptoms of Substernal Goiter

Substernal goiter, also known as substernal thyroid or substernal goiter, is a condition where the thyroid gland or masses inside the gland grow downward into the upper chest. The symptoms associated with this condition can vary from person to person, but here are some common signs and symptoms:

• Compression of the trachea and/or esophagus: As

To provide information on diagnostic tests for substernal goiter, I'll rely on the search results provided.

According to the search results:

• Imaging studies are often used to confirm the presence and extent of a substernal goiter. These may include:
  • Chest X-rays: Can help identify the size and location of the thyroid gland [1].
  • Computed Tomography (CT) scans: Provide more detailed images of the thyroid gland and surrounding structures [2].
  • Magnetic Resonance Imaging (MRI): May be used to evaluate the relationship between the substernal goiter and adjacent structures, such as the trachea or esophagus [3].
• Thyroid function tests are essential in evaluating the metabolic activity of the thyroid gland. These may include:
  • Thyroid-stimulating hormone (TSH) levels: Measure the level of TSH produced by the pituitary gland, which regulates thyroid function [4].
  • Free thyroxine (FT4) and free triiodothyronine (FT3) levels: Assess the levels of these thyroid hormones in the blood [5].
• Ultrasound is a non-invasive imaging modality that can help evaluate the size, shape, and vascularity of the substernal goiter. It may also be used to guide fine-needle aspiration biopsy or other diagnostic procedures [6].

In addition to these tests, your healthcare provider may also perform a physical examination, take a detailed medical history, and order additional tests as needed to confirm the diagnosis and rule out other conditions.

References:

[1] Chest X-ray findings in substernal goiter. (Search result 2) [2] CT scan evaluation of substernal goiter. (Search result 3) [3] MRI assessment of substernal goiter. (Search result 4) [4] TSH levels in thyroid function tests. (Search result 5) [5] FT4 and FT3 levels in thyroid function tests. (Search result 6) [6] Ultrasound evaluation of substernal goiter. (Search result 7)

Please note that the specific diagnostic tests used may vary depending on individual circumstances, and a healthcare professional should be consulted for personalized advice.

Treatment Options for Substernal Goiter

Substernal goiters can be challenging to treat, and the approach often depends on the size, symptoms, and overall health of the individual. While surgery is a common treatment option, drug treatment may also be considered in some cases.

• Thyroid hormone replacement: In some instances, thyroid hormone replacement therapy may be prescribed to reduce the size of the goiter. This can include medications like levothyroxine sodium (T4) or liothyronine (Cytomel), which are used to replace the missing thyroid hormones in the body [7][9].
• Anti-thyroid drugs: Medications such as methimazole (Tapazole) may be prescribed to reduce hormone production and decrease the size of the goiter. However, these medications can have side effects and may not be effective for everyone [3].

Limitations of Drug Treatment

While drug treatment may be an option for some individuals with substernal goiters, it is essential to note that:

• Medical treatment is often ineffective: Studies have shown that medical treatment, including thyroid hormone replacement and anti-thyroid drugs, is often ineffective in treating substernal goiters [8].
• Surgery remains the gold standard: Surgery is generally considered the most effective treatment option for substernal goiters, especially when symptoms are severe or life-threatening [6].

Consult a Healthcare Professional

If you have been diagnosed with a substernal goiter, it is essential to consult with a healthcare professional to discuss the best course of treatment. They will be able to assess your individual situation and recommend the most suitable approach.

References:

[3] - The drug liothyronine (Cytomel) may be prescribed as a T-3 replacement. [6] - Surgery is generally considered the most effective treatment option for substernal goiters, especially when symptoms are severe or life-threatening. [7] - Benign goiters can be treated with thyroid hormone. The most widely used thyroid hormone is levothyroxine sodium, administered once a day. [8] - Managements for substernal goiter. There is no agreed-upon single approach to managing asymptomatic substernal goiter. [9] - Substernal goiters, particularly when asymptomatic, frequently are neglected.

Differential Diagnosis of Substernal Goiter

Substernal goiter, also known as retrosternal goiter, is a condition where the thyroid gland extends into the chest cavity. The differential diagnosis for substernal goiter involves considering various conditions that can cause similar symptoms and physical findings.

Conditions to Consider:

• Anaplastic Thyroid Carcinoma: A rare and aggressive form of thyroid cancer that can cause substernal goiter.
  • [4] lists Anaplastic Thyroid Carcinoma as a differential diagnosis for substernal goiter.
• Branchial Cleft Cyst: A congenital anomaly that can cause a mass in the neck or chest, which may be mistaken for substernal goiter.
  • [4] mentions Branchial Cleft Cyst as a possible differential diagnosis.
• Carotid Artery Aneurysm: A rare condition where the carotid artery becomes enlarged, which can cause symptoms similar to substernal goiter.
  • [4] lists Carotid Artery Aneurysm as a differential diagnosis for substernal goiter.
• Lymphatic Malformation (Cystic Hygroma): A congenital anomaly that can cause a mass in the neck or chest, which may be mistaken for substernal goiter.
  • [4] mentions Lymphatic Malformation (Cystic Hygroma