Thyroid CANCER

Thyroid CANCER

Thyroid neoplasm or thyroid cancer usually refers to any of four kinds of malignant tumors of the thyroid gland: papillary, follicular, medullary or anaplastic.^[1] Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men.^[1] Papillary and follicular tumors are the most common. They grow slowly and may recur, but are generally not fatal in patients under 45 years of age. Medullary tumors have a good prognosis if restricted to the thyroid gland and a poorer prognosis if metastasis occurs. Anaplastic tumors are fast-growing and respond poorly to therapy.
Thyroid nodules are diagnosed by ultrasound guided fine needle aspiration (USG/FNA) or frequently by thyroidectomy (surgical removal and subsequent histological examination). As thyroid cancer can take up iodine, radioactive iodine is commonly used to treat thyroid carcinomas, followed by TSH suppression by high-dose thyroxine therapy.

Symptoms

Most often the first symptom of thyroid cancer is a nodule in the thyroid region of the neck.^[1] However, many adults have small nodules in their thyroids. But typically under 5% of these nodules are found to be malignant. Sometimes the first sign is an enlarged lymph node. Later symptoms that can be present are pain in the anterior region of the neck and changes in voice.
Thyroid cancer is usually found in a euthyroid patient, but symptoms of hyperthyroidism or hypothyroidism may be associated with a large or metastatic well-differentiated tumor.
Nodules are of particular concern when they are found in those under the age of 20. The presentation of benign nodules at this age is less likely, and thus the potential for malignancy is far greater.

Diagnosis

After a nodule is found during a physical examination, a referral to an endocrinologist, a thyroidologist or otolaryngologist may occur. Most commonly an ultrasound is performed to confirm the presence of a nodule, and assess the status of the whole gland. Measurement of thyroid stimulating hormone and anti-thyroid antibodies will help decide if there is a functional thyroid disease such as Hashimoto's thyroiditis present, a known cause of a benign nodular goiter.

Treatment

If the nodule is benign, patients may receive thyroxine therapy to supress thyroid-stimulating hormone and should be reevaluated in 6 months.^[1]
If the nodule is malignant or has indeterminate cytologic features, it may require surgery. Common surgeries include thyroidectomy, lobectomy, and tracheostomy.^[1]
Radioactive Iodine-131 is used in patients with papillary or follicular thyroid cancer for ablation of residual thyroid tissue after surgery and for the treatment of thyroid cancer. Patients with medullary, anaplastic, and most Hurthle cell cancers do not benefit from this therapy.^[1]
External irradiation may be used when the cancer is unresectable, when it recurs after resection, or to relieve pain from bone metastasis.^[1]