Revision 19 for 'Goiter'

Goiter (rarely thyromegaly) refers to enlargement of the thyroid gland. It can occur from multiple conditions.

The definition of a goiter depends on age and sex; below are the upper limits of normal for thyroid gland volume ¹:

• adult males: 25 mL
• adult females: 18 mL
• 13-14 years: 8-10 mL
• 3-4 years: 3 mL
• neonate: 0.8-1.5 mL

Epidemiology

The prevalence of goiter varies widely depending on the level of iodine deficiency. In severely iodine-deficient areas the prevalence may be as a high as 80%. Goiter is more common in women (M:F = 1:4) and incidence declines with age ⁵.

Pathology

The thyroid gland may become so enlarged that it becomes a substernal goiter.

Etiology

The causes of goiter are diverse ^2,3:

• non-toxic simple goiter (e.g. from iodine deficiency)
• Graves disease
• multinodular goiter
• Hashimoto thyroiditis
• thyroid cancer
• goitrogens
  • drugs: lithium, amiodarone, etc.
  • diet: cabbage, sprouts, etc.
• depositional disease, e.g. amyloidosis

Radiographic features

CT

Thyroid volume can be estimated by measuring each lobe and applying the following correction factor for an ellipsoid formula ⁶:

• height (cm) x width (cm) x depth (cm) x 0.529*

* various correction factors between 0.494-0.554 have also been proposed ⁶

History and etymology

Goiter derives from the old French "goitron" meaning gullet. Goitron comes from the Latin "guttur" meaning throat.

Differential diagnosis

See main article: midline neck mass