Thyroid nodule

Definition

A thyroid nodule is a growth (lump) in the thyroid gland. The thyroid gland is located at the base of the neck.

Alternative Names

Thyroid tumor; Thyroid adenoma; Thyroid carcinoma; Thyroid incidentaloma

Causes

Thyroid nodules are growths of cells in the thyroid gland. These growths can be:

• Not cancer (benign) or thyroid cancer
• Fluid-filled (cysts) or made up of thyroid gland cells
• One nodule or a group of small nodules

Thyroid nodules are more common in women than in men. A person's chance of getting a thyroid nodule increases with age.

Only a few thyroid nodules are due to thyroid cancer. A thyroid nodule is more likely to be cancer if you:

• Have a hard nodule
• Have a nodule that is stuck to nearby structures
• Have a family history of thyroid cancer
• Have a hoarse voice
• Are younger than 20 or older than 70
• Have a history of radiation exposure to the head or neck
• Are male

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

• Hashimoto's disease
• Lack of iron in the diet

Symptoms

Most thyroid nodules do not cause symptoms.

Large nodules can press against other structures in the neck, causing symptoms such as:

• Goiter or an enlarged thyroid gland or lump(s) in the neck
• Hoarseness or changing voice
• Pain in the neck
• Problems breathing
• Problems swallowing 

Nodules that produce thyroid hormones will likely cause symptoms of overactive thyroid gland, including:

• Clammy skin
• Fast pulse
• Increased appetite
• Nervousness
• Restlessness
• Skin blushing or flushing
• Weight loss

Thyroid nodules are sometimes found in people who have Hashimoto's disease, which may cause symptoms of an underactive thyroid gland, such as:

• Dry skin
• Face swelling
• Fatigue
• Hair loss
• Intolerance to cold
• Weight gain without trying

Exams and Tests

Very often, nodules produce no symptoms. Doctors will find thyroid nodules only during a routine physical exam or imaging tests that are done for another reason. However, thyroid nodules that are big enough to feel during a physical exam occur in a few people.

If the doctor finds a nodule or you have symptoms of a nodule, the following tests may be done:

• TSH level and other thyroid blood tests
• Thyroid ultrasound
• Thyroid scan
• Fine needle aspiration biopsy 

Treatment

Your health care provider may recommend surgery to remove all or part of your thyroid gland if the nodule is:

• Believed to be making too much thyroid hormone
• Causing symptoms such as swallowing or breathing problems
• Due to thyroid cancer
• Not able to be diagnosed as cancer or not cancer

Patients with nodules that are making too much thyroid hormone may be treated with radioactive iodine. This treatment reduces the size and activity of the nodule. Pregnant women should not be given this treatment.

Both surgery to remove thyroid gland tissue and radioactive iodine treatment carry risks of long-term thyroid problems.

For noncancerous nodules that do not cause symptoms and are not growing, the best treatment may be:

• Careful follow-up with a physical exam and ultrasound
• A thyroid biopsy repeated 6 - 12 months after diagnosis, especially if the nodule has grown

Another possible treatment is ethanol (alcohol) injection into the nodule to shrink it.

Outlook (Prognosis)

Noncancerous thyroid nodules are not life threatening. Many do not require treatment. Follow-up exams are enough.

The outlook for thyroid cancer depends on the type of cancer.

When to Contact a Medical Professional

Call your health care provider if you feel or see a lump in your neck, or if you experience any symptoms of a thyroid nodule.

If you have been exposed to radiation in the face or neck area, call your health care provider. A neck ultrasound can be done to look for thyroid nodules.

References

Gharib H, Papini E, Paschke R, 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.

Kim M, Ladenson P. Thyroid. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 233.

Schlumberger MJ, Filetti S, Hay ID. Nontoxic Diffuse and Nodular Goiter and Thyroid Neoplasia. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 14.

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