Thyroid Nodules

Thyroid nodules are common...

Thyroid nodules are common.  Clinically apparent nodules (ones your doctor can feel on examination of your neck) can be found in 4 % of adults.

Thyroid nodules are more common in women: 6.4 % women, 1.5 % men.

20% of women have nodules that can be seen on a thyroid ultrasound.

50% of women older than age 50 have nodules that can be seen on a thryoid ultrasound.  The incidence of thyroid nodules goes up with age.

What kind of conditions cause nodules in the thyroid?

Only 5 - 6.5 % of thyroid nodules are cancer.  Therefore most nodules are benign.  There are many things that can cause a nodule in the thyroid:

Benign Thyroid Nodules Thyroid Cancer
Simple or Colloid Cyst Papillary thyroid cancer
Follicular adenoma (benign tumor) Follicular thyroid cancer
Thyroiditis (inflamed thyroid) Medullary thryoid cancer
Parathyroid gland (adenoma, hyperplasia) Anaplastic thyroid cancer
  Thyroid Lymphoma
  Metastasis (cancer spread to thyroid from elsewhere in the body)

Risk of Cancer

The risk of a thyroid nodule being cancer is influenced by several factors:

Age Age < 30 or > 60 increases risk, Children are at 2x higher risk
Sex Male are at 2x higher risk
Radiation Exposure to Head/Neck for treatment (acne, tonsils, enlarged thymus, Hodgkin's, etc.), radiation spill (Chernobyl) Nodules occur in 20-27% of exposed

Papillary cancer occurs in 30-33% of these nodules