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Johns Hopkins Symptoms and Remedies

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Thyroid Nodules

What is it?

Thyroid nodules are solid lumps arising in the thyroid gland. The thyroid gland, at the base of the neck, produces thyroid hormone, which regulates body growth and metabolism. Nodules usually grow slowly over many years. They appear singularly or in clusters (benign nodular goiter) and usually are not detectable until they have grown to at least one centimeter in size. The greatest concern of a solitary nodule is the possibility of cancer, although this is uncommon. The vast majority of solitary nodules are cysts or benign tumors (adenomas), which affect about 4 percent of the adult population. Nodules are classified according to their production of thyroid hormone. "Warm" nodules mimic normal thyroid cells in this regard. "Hot" nodules overproduce thyroid hormone and are virtually always benign (see Hyperthyroidism for more information). "Cold" nodules underproduce thyroid hormone.

What Causes It?

  • The cause of thyroid nodules is unknown, but incidence is higher among people who received x-ray treatment to the thyroid area in infancy or childhood. Women are affected more often than men.

Prevention

  • There is no known way to prevent thyroid nodules.

Diagnosis

  • Patient history including any radiation treatments in infancy or childhood.
  • Physical examination to determine whether the lump is solitary or in a cluster.
  • Thyroid function tests to measure thyroid hormone levels. Patients with hyperthyroidism usually need a scan to determine whether their nodule(s) are hyperfunctioning or not.
  • Ultrasound scans to identify cysts.
  • Fine-needle biopsy (use of a small-gauge needle and syringe to take a tissue sample for examination under a microscope) is used to rule out cancer.

How to Treat It

  • If a needle biopsy shows no evidence of cancer and thyroid function tests are normal, regular follow-up examinations and thyroid function tests are all that is required.
  • If the nodule is a fluid-filled cyst, needle drainage may be done.
  • Hot nodules associated with hyperthyroidism are treated with radioactive iodine or surgery.
  • Thyroidectomy is recommended if cancerous cells are detected in a needle biopsy.
  • Treatment for hypothyroidism may subsequently be needed if excess thyroid tissue is removed or destroyed by radioactive iodine therapy (see Hypothyroidism for more information).
  • If the findings are equivocal on fine-needle biopsy, thyroid hormone may be administered to observe whether the nodule shrinks over the ensuing six to 12 months.

When to Call a Doctor

  • Call a doctor as soon as possible if you detect an unusual lump in your neck. A complete evaluation is imperative.