Thyroid nodule

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Thyroid adenoma; Thyroid carcinoma; Thyroid incidentaloma

Thyroid nodules are growths of cells in the thyroid glands. These growths can be benign (non-cancerous) or malignant (cancerous). Some nodules are fluid-filled (cysts), while others are completely made of thyroid gland cells. Sometimes, what feels like one nodule will actually be a collection of small nodules close together.

Thyroid nodules that are big enough to feel during a physical exam occur in 5 - 7% of the population. Smaller nodules occur in as many as 50% of people aged 60 or older. Thyroid nodules are more common in women than in men. A person's chance of a thyroid nodule increases with age.

Only 4 - 5% of thyroid nodules are cancerous. (See: Thyroid cancer)

The following characteristics increase the risk for a cancerous nodule:

• Family history of medullary thyroid carcinoma
• Family history of multiple endocrine neoplasia Type II
• A hard nodule
• A nodule that is stuck to nearby structures
• Vocal cord paralysis

Other risk factors for a cancerous nodule include:

• Male gender
• Age -- younger than 20 years or older than 70
• History of radiation exposure to the head or neck

Causes of thyroid nodules are not always found, but can include:

• Iodine deficiency
• Suppression of thyroid hormone
• Hashimoto's disease

Review Date: 05/11/2006
Reviewed By: Rita Nanda, MD, Department of Medicine, Section of Hematology/Oncology, University of Chicago Medical Center, Chicago, IL. Review provided by VeriMed Healthcare Network.