Evaluation of the thyroid nodule

Clinically detectable thyroid nodules occur in up to 4% of the population in the United States. With ultrasound, nodules may be found in up to 50% of those over 50 years of age.

The author reviews his own experience as well as that of others to define a sound clinical approach to the differential diagnosis and detection of thyroid cancer.

Prior neck irradiation is a risk factor for thyroid malignancy. The association of a thyroid nodule with enlarged lymph nodes or fixation of the nodule to strap muscles or the trachea suggests malignancy. A diffusely multinodular gland is usually benign.

Thyroid function tests rarely help a differential diagnosis. Fine-needle aspiration is the "gold standard" for diagnosis. Tiny "incidentalomas" are often followed with repeat monitoring for change of size or character.