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, incidence, and risk factors
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
