Thyroid nodules are common and a only a small percentage are cancerous. So removal of all thyroid nodules is not practical. Therefore, the otolaryngologist/head and neck surgeon must determine which nodules are at the greatest risk for being cancerous.
Cancer Risk
Many more woman than men have thyroid nodules, but a nodule in a man is more likely to be cancerous. Older people have more thyroid nodules than younger people. A thyroid nodule in a person younger than age 40 years, however, has a greater chance of being malignant. The patient's background is also important. Family history or past exposure to low dose radiation, for example, should be considered.
Evaluation
If a person is considered to be at risk for thyroid cancer, testing may be ordered. A FNA (fine needle aspirate) of the mass can be performed, occasionally with ultrasound guidance. The cells obtained from this test are examined by a pathologist for malignancy. The FNA is the single best test for malignancy, but it is not fool proof. Thyroid scans and ultrasound tests might also be considered, but increasingly computed tomography (CT) scans are being employed.
Cancer Types
There are four main types of thyroid cancer: papillary, follicular, medullary , and anaplastic .Ocassionally , lymphoma is found in the thyroid gland. Papillary cancer accounts for 80% of thyroid malignancies. Papillary and follicular cancers are considered well differentiated tumors with the least aggressive behavior.
Treatment Therapy for the well differentiated thyroid cancers include surgical removal of the thyroid gland and tumor. Total thyroidectomy is preferred. There is a slight increased risk of injury to the nerves to the voice box ( recurrent laryngeal nerves ) and the glands that control the bodies calcium regulation ( parathyroid glands ) with total versus subtotal thyroid gland removal . The patient and surgeon must weigh the risks and benefits of each procedure. A modified neck dissection (removal of lymph nodes) may also be performed if lymph node involvement is detected. Postoperative treatment with radioactive iodine and/or thyroid hormone suppression may be used to decrease the risk of tumor recurrence or spread.
Medullary carcinoma may run in families (20% of cases). In addition, other endocrine tumors may be associated with this disease ( MEN or multiple endocrine neoplasms ) and require evaluation. All first degree relatives of the patient should be evaluated for the disease or risk for later development of medullary cancer. Total or subtotal thyroidectomy is the treatment of choice along with elective neck dissection .
Anaplastic carcinoma is a rare thyroid cancer. It is also extremely aggressive with a poor prognosis. If possible, total thyroidectomy is recommended. Often, removal is not possible and biopsy with placement of a tracheotomy is performed.
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