Thyroid Nodule

From: http://www.nlm.nih.gov/medlineplus/ency/article/007265.htm

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

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

Only a few thyroid nodules are cancerous. (See: Thyroid cancer)

The following characteristics increase the chances that a thyroid nodule is cancerous:
A hard nodule
A nodule that is stuck to nearby structures
Family history of multiple endocrine neoplasia Type II
Family history of thyroid cancer, especially medullary thyroid carcinoma
Hoarse voice due to vocal cord paralysis
Age -- younger than 20 years or older than 70
History of radiation exposure to the head or neck
Male gender

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

Hashimoto's disease
Iodine deficiency

Symptoms
Most thyroid nodules produce no symptoms.
Large nodules can press against other structures in the neck. Symptoms may include:

Difficulty breathing
Difficulty swallowing
Goiter
Hoarseness or changing voice
Pain in the neck
Nodules that produce thyroid hormones will cause symptoms of hyperthyroidism,
including:
Bounding pulse
Clammy skin
Increased appetite
Nervousness
Restlessness
Skin blushing or flushing
Weight loss
Thyroid nodules are sometimes found in people who have Hashimoto's disease. Hashimoto's disease may cause hypothyroidism, with symptoms such as:
Dry skin
Facial swelling
Fatigue
Hair loss
Intolerance to cold
Unintentional weight gain

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:

Fine needle aspiration biopsy
Thyroid scan
Thyroid ultrasound
TSH level

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

Cancerous
Believed to be making your thyroid overactive (hyperthyroid)
Cannot be diagnosed as cancer or non-cancer
Cause symptoms such as swallowing or breathing problems
Patients with overactive nodules may be treated with radioactive iodine, which reduces the size and activity of the nodule. However, in rare cases the treatment can cause hypothyroidism and inflammation of the thyroid gland (radiation-induced thyroiditis). Pregnant women should not be given this treatment. Women being treated with radioactive iodine should not get pregnant.

Levothyroxine (thyroid hormone) is a drug that suppress the production of the thyroid hormone T4. A doctor may prescribe levothyroxine to treat non-cancerous nodules only in special cases.

Careful follow-up is the only recommended treatment for benign nodules that do not cause symptoms and are not growing. A thyroid biopsy may need to be repeated 6-12 months after diagnosis. An ultrasound may be repeated as well.

Other possible treatments include ethanol (alcohol) injection into the nodule and laser therapy.

Outlook (Prognosis)
Noncancerous thyroid nodules are not life threatening. Many do not require treatment, only follow-up. Noncancerous nodules that do need treatment have an excellent outlook.

The outlook for cancerous nodules depends on the type of cancer.

See also: Thyroid cancer

Possible Complications
Hyperthyroidism is a common complication of non-cancerous thyroid nodules.

Complications of treatment can include:

Hoarse voice if vocal cord nerves are damaged during surgery
Hypothyroidism from surgery or radioactive iodine therapy
Low blood calcium (hypocalcemia) from hypoparathyroidism if parathyroid glands are accidentally damaged or removed during surgery
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.

Prevention
The reason for most thyroid nodules is unknown. A diet with enough iodine will help prevent some nodules.

Alternative Names
Thyroid tumor; Thyroid adenoma; Thyroid carcinoma; Thyroid incidentaloma

References
Alexander EK. Approach to the patient with a cytologically indeterminate thyroid nodule. Journal of Clinical Endocrinology and Metabolism. Nov 2008;93(11).

Ladenson P, Kim M. Thyroid. In: Goldman L and Ausiello D, eds. Goldman: Cecil Medicine. 23rd ed. Philadelphia, Pa:Saunders; 2007:chap 244.

AACE/AME. American Association of Clinical Endocrinologists and Associazione Medici Endocrinologi. Medical Guidelines for Clinical Practice for the Diagnosis and Management of Thyroid Nodules. Endocr Pract. 2006;12:63-102.

Update Date: 4/29/2009
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Deborah Wexler, MD, Assistant Professor of Medicine, Harvard Medical School, Endocrinologist, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

Blogger Comment:
For nodule investigation many of endocrinologists check TSH and FNA (fine needle aspiration. Many do thyroid ultrasound to see if has some features of cancer as well to get accurate measurment of the nodule for future follow up. Thyroid ultrasound is used as well for fine needle aspiration if nodule is not well accessible. Thyroid scan is usually done if TSH is low or FNA shows follicular nodule.