About Your Diagnosis

A thyroid nodule is any discrete lump on the thyroid gland. Thyroid nodules may be caused by a localized infection, a cyst, a benign tumor, or a malignant tumor of the thyroid. The vast majority of nodules are benign tumors or fluid-filled cysts; however, some are a thyroid cancer. For this reason, all thyroid nodules should be investigated. Thyroid nodules are extremely common, occurring in up to 5% of the population. Many individuals do not realize they have a nodule. Thyroid nodules may be noticed by patients when they look in the mirror, or by a physician at a routine office visit. Nodules may be noted by radiologists when images are taken of the chest or neck. Once detected, two important questions must be answered:
• Is the thyroid functioning normally?
• Is the nodule benign or malignant?
Thyroid function blood tests will determine whether the thyroid is functioning normally. If it is overactive, a special test called a radioactive iodine scan is performed to see whether this is a solitary, hyperfunctioning nodule that requires medical treatment. Most patients have normal thyroid function and require a fine- needle aspiration biopsy (FNAB) to ensure that the nodule is not a cancer. This may be performed directly or under ultrasound guidance, depending on the location of the nodule. The majority of nodules are benign and easily treated with medications that help prevent nodule growth. Some patients may require surgery to remove benign thyroid nodules if they cause local compressive symptoms in the neck. Thyroid cancer is cured by surgery when detected before spread outside of the thyroid gland. Long-term survival is the rule, even in patients in whom the entire cancer cannot be removed at surgery. Certain types of thyroid cancers are more aggressive, however.
Living With Your Diagnosis
Some patients may have no symptoms of their disease. Others may notice a soft, painless swelling in the area of the thyroid gland. Hot nodules cause symptoms of anxiety, sweating, weight loss, hunger, and tremor. A rock-hard nodule that rapidly grows and is associated with hoarseness or difficulty swallowing is suggestive of cancer, especially if other lumps are noted elsewhere in the neck. Most nodules are benign cold nodules, having no effect on an individual’s health. Hot nodules may cause hyperthyroidism. Cancerous nodules may spread beyond the thyroid.
Treatment
Large nodules that compress the windpipe, or nodules found to be suspicious of cancer at FNAB, are surgically removed. If tumor was left behind in the neck, radioactive iodine is given as a single tablet by mouth to destroy the remaining cancer cells. This treatment will make the patient hypothyroid, and replacement thyroid hormone therapy is given with levothyroxine. Cystic nodules that contain fluid are drained at the time of FNAB. Benign, solid nodules are diagnosed by FNAB and treated with levothyroxine to help prevent further nodule growth. Possible complications of surgery include local bleeding, infection, a low calcium level caused by parathyroid gland damage, or vocal damage caused by cutting a nerve that runs through the neck to the vocal cords. In experienced hands, complications occur in less than 2% of operations. Excess hormone replacement for benign nodules can lead to mild hyperthyroidism. Radioactive iodine therapy may cause swelling and drying of the parotid or salivary glands. Very high doses have been associated with chronic lung disease.
The DOs
• Obtain a FNAB of any prominent nodule in the thyroid.
• Find an experienced surgeon if necessary.
• Examine your neck regularly.
• Tell your doctor if you have had a history of radiation therapy to the neck, or a family history of thyroid cancer.
The DON’Ts
• Don’t speak or swallow while the doctor performs the FNAB.
• Don’t obtain a radioactive iodine scan to evaluate the nodule unless blood tests confirm that you are hyperthyroid. You will still need a FNAB unless you are hyperthyroid as a result of a hot nodule.
When to Call Your Doctor
• You notice any new nodule in the thyroid or any rapid growth of an old nodule, even if a biopsy specimen of this nodule had been obtained in the past and found to be benign.
• You have hoarseness, difficulty swallowing, or difficulty breathing.
• You have bleeding, fever, or infection after FNAB or surgery.
• You feel weak or notice facial twitching, or numbness around the lips after thyroid surgery. These are signs of a low blood calcium level and require immediate attention.
Websites: The American Thyroid Association: http://www.thyroid.org/patient
American Association of Clinical Endocrinologists: http://www.aace.com