Endocrine: Goiter

Goiter

Definition

Definition: Any Enlargement of the Thyroid Gland
Types:
- Toxic: Functional
- Nontoxic: Not Functional

Causes

Toxic Causes:
- *See Endocrine: Hyperthyroidism
Nontoxic Causes:
- Iodine Deficiency – Most Common Identified Cause
- Physiologic (Puberty or Pregnancy)
- Goitrogens (Bamboo Sheets, Cabbage, Maize & Sweet Potatoes)
- Dysmorphogenesis
- Radiation Exposure
- Low Grade TSH Stimulation

Substernal Goiter Origins

Primary (Rare)
- Originates in Mediastinum
- Vessels from Innominate Artery
Secondary (More Common)
- Migrates to Mediastinum
- Vessels from Thyroid Arteries

Presentation

Toxic Symptoms:
- *See Endocrine: Hyperthyroidism
Nontoxic Symptoms: Mostly Due of Mass Effect/Compression
- Neck Pain
- Dysphagia
- Dyspnea
- Hoarseness

Diagnosis

Initial Evaluation: US & Labs (TSH & Free T4/T3)
Suspicious or Nonfunctioning Nodules Require FNA

Treatment

If Small & Asymptomatic: Nothing
Primary Treatment: Surgery
- Indications:
  - Large > 4 cm
  - Dysphagia
  - Airway Compromise
  - Local Discomfort
  - Substernal Location (Risk of Hidden Malignancy & Further Extension Can Require More Extensive Surgery in the Future)
- Approach:
  - Unilateral Enlargement: Lobectomy
  - Bilateral Enlargement: Total/Near-Total Thyroidectomy
  - Substernal Goiters Can Mostly Be Removed Through a Cervical Incision & Rarely Require Sternotomy

Goiter ¹

Substernal Goiter (Arrow) on CT ²

References

Wikimedia Commons. (License: Public Domain)
Suut S, Al-Ani Z, Allen C, Rajiah P, Durr-E-Sabih, Al-Harbi A, Al-Jahdali H, Khan AN. Pictorial essay of radiological features of benign intrathoracic masses. Ann Thorac Med. 2015 Oct-Dec;10(4):231-42. (License: CC BY-NC-SA-3.0)