Thyroid Nodules and Cancer
Fact Sheet
What is the thyroid?
The thyroid is a butterfly-shaped gland, located at the front base of the neck, which secretes hormones that
regulate the body’s metabolism.
What are thyroid nodules?
Thyroid nodules are abnormal growths of cells on the thyroid gland. They are a common clinical problem, which
occur more frequently in women and the elderly. Incidence rates increase with age, with a prevalence of almost
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50% in people aged 50 and older. Most – an estimated 95% -- thyroid nodules are benign. However, when they
are discovered, physicians will usually take steps to rule out thyroid cancer.
How common is thyroid cancer?
Thyroid cancer is the fastest increasing cancer in the United States, with an estimated 56,460 new cases
expected in 2012, according to the American Cancer Society. The disease is most prevalent in women,
accounting for 3 out of every 4 cases. Thyroid cancer is highly treatable when detected early, with a 5-year
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survival rate of 97% for all thyroid cancer patients.
What are the symptoms of thyroid cancer?
The most common symptom of thyroid cancer is a nodule, or lump, in the neck, which is typically found by the
patient, felt by a healthcare provider during a clinical examination or discovered on an imaging study such as a
carotid ultrasound. Other symptoms may include difficulty breathing or swallowing, neck pain, hoarseness or
swollen lymph nodes.
How are thyroid nodules diagnosed?
A typical work-up for a patient with a thyroid nodule includes a blood test to determine if the thyroid is functioning
properly; ultrasound imaging to determine the size and other characteristics of the nodule; and a fine needle
aspiration (FNA) biopsy to establish if the nodule is benign or malignant.
What is a thyroid fine needle aspiration (FNA)?
A thyroid fine needle aspiration (FNA) is a minimally invasive technique, typically conducted in a doctor’s office,
used to evaluate a thyroid nodule to determine if cancer is present or not. The procedure involves a doctor
inserting a short thin needle into the nodule to obtain cells for examination under a microscope. An estimated
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450,000 thyroid nodule FNAs are performed in the U.S. each year, but they are challenging to interpret,
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producing inconclusive results in 15-30% of cases.
Why are thyroid FNAs so hard to interpret?
Thyroid cancer is a complex disease with hard-to-distinguish cell structures. This limits what can be diagnosed
under the microscope, particularly with the small number of cells that are obtained via FNA sampling.
What happens if a patient has an inconclusive thyroid FNA result?
Current medical guidelines recommend that most of these patients have surgery to remove all or part of their
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thyroid. This procedure, called a thyroidectomy, enables a pathologist to examine the larger amount of tissue
extracted in order to determine definitively if cancer is present or not. Most of these patients (70-80%) turn out to
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have benign conditions.
How risky is thyroid surgery and what are the potential complications?
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Such complications include recurrent
Thyroidectomies pose a 2-10% risk of serious complications.
laryngeal (voice box) nerve damage, calcium deficiency, re-bleeding and wound infection.
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What are the long-term effects of having one’s thyroid removed?
Most patients who have their thyroid removed take daily hormone drugs to keep their thyroid hormone levels in
balance. This can be a challenging process, with studies showing that, at any given time, 40% of such patients
still have a thyroid hormone imbalance. Insufficient thyroid hormone levels (hypothyroidism) can produce
symptoms including depression, low energy and high cholesterol, while excessive levels (hyperthyroidism) can
cause symptoms such as rapid or irregular heartbeat, sweating, nervousness and irritability.
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Cooper DS et al. Revised American Thyroid Association Management guidelines for patients with thyroid nodules and differentiated thyroid
cancer. Thyroid. 2009;19:1167-1214.
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Gharib H, et al. American Association of Clinical Endocrinologists, Associazione Medici Endocrinologi, and European Thyroid Association
Medical guidelines for clinical practice for the diagnosis and management of thyroid nodules. Endocr Pract. 2010;16 Suppl 1:1-43.
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Baloch ZW et al. Diagnostic terminology and morphologic criteria for cytologic diagnosis of thyroid lesions: a synopsis of National Cancer
Institute Thyroid Fine-Needle Aspiration State of the Science Conference. Diagn Cytopathol. 2008;36:425-437.
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Bergenfelz A, Jansson S, Kristoffersson A, et al. Complications to thyroid surgery: results as reported in a database from a multicenter audit
comprising 3,660 patients. Langenbeck’s Arch Surg. 2008;393:667-673.
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Sosa JA, Bowman HM, Tielsch JM, Powe NR, Gordon TA, Udelsman R. The importance of surgeons’ experience for clinical and economic
outcomes from thyroidectomy. Ann Surg. 1998;228:320-330.
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Shrime MG, Goldstein DP, Seaberg RM, et al. Cost effective management of low-risk papillary thyroid carcinoma. Arch otolaryngol Head
Neck Surg. 2007;133:1245-1253.
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Esnaola NF, Cantor SB, Sherman SI, Lee JE, Evans DB. Optimal treatment strategy in patients with papillary thyroid cancer: a decision
analysis. Surgery. 2001;130:921-930.
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Hundahl SA, Cady B, Cunningham MP, et al. Initial results from a prospective cohort study of 5583 cases of thyroid carcinoma treated in the
United States during 1996. An American College of Surgeons Commission on Cancer Patient Care Evaluation Study. Cancer. 2000;89(1):202217.
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