Goiter%20nontoxic%20(simple)--%20diffuse%20-and-%20multinodular Diagnosis

• Diagnosis of exclusion to rule out goiter due to hypothyroidism, hyperthyroidism, autoimmune thyroiditis, invasive fibrous thyroiditis, medications and iodine deficiency or excess

• Cosmetic complaints (disfigurement due to enlarged goiter), obstructive complaints, growth rate and family history

• Inspect neck (check size, nodules and texture of goiter), detect obstructive signs (stridor, Pemberton’s sign, plethora, etc)
  
  • Nontoxic multinodular goiter: Multiple, distorted nodules of varying sizes
  • Diffuse nontoxic goiter: Symmetrical, enlarged, non-tender, soft gland without nodules 
• A retrosternal goiter may not be evident on physical exam

Thyroid Function Tests

• Measure serum thyroid stimulating hormone (TSH) and free thyroxine (FT₄) levels [measure serum free triiodothyronine (FT₃) levels if FT₄ is normal and in nodular goiter] to exclude hyperthyroidism and hypothyroidism
  
  • Euthyroid state (normal serum FT₃ and FT₄ levels) may suggest diagnosis of goiter (simple/nontoxic)
  • TSH suppression may develop due to increasing goiter size
  • FT₃ toxicosis may occur in multinodular goiter
• Measure: Thyroid peroxidase (TPO) antibodies, thyroglobulin antibodies and TSH receptors antibodies to exclude autoimmune thyroid diseases

Fine Needle Aspiration Cytology (FNAC)

• Performed to rule out malignancy in cases of suspicious nodules
• Indicated if the patient has a history of rapid growth, pain, or tenderness, also if there is unusual firmness in one region of the goiter; or sonographically detected nodules with indeterminate or suspicious sonographic features
• May be performed with ultrasound guidance in cases of nonpalpable nodules with diameter of ≥1 cm

Pulmonary Function Tests

• Performed to determine the degree of airway obstruction

Thyroid Ultrasound

• Preferred and most useful imaging modality to guide disease management and treatment of nodular goiter
• Gold standard for measuring thyroid size, identifying the structure and evaluating diffuse changes in the thyroid gland
• Recommended in patients with physical examination revealing thyroid asymmetry, focal firm consistency or tenderness, rapid growth of goiter, and goiter with normal TSH level and negative TPO antibodies
• Provides a measure of goiter growth rate over time and posttreatment
• Determines extent of nodularity

Thyroid Scintigraphy

• Visualizes goiter, determines its inherent properties; identifies hot and cold nodules
• Recommended in patients with solitary thyroid nodule or multinodular goiter with low TSH levels
  

X-ray of the Neck and Upper Mediastinum

• Used to determine the presence of tracheal compression

Computed Tomography (CT)/Magnetic Resonance Imaging (MRI)

• Perform CT/MRI (to evaluate the anatomy of the goiter and the extent of substernal extension), if substernal goiters are suspected
  • Pemberton’s sign, obstructive signs and symptoms suggest substernal goiter
  • Substernal goiter may obstruct thoracic inlet and compress trachea