Thyroid Cancer Diagnosis Follicular Carcinoma

Follicular thyroid cancer, also called “follicular carcinoma” or “follicular thyroid carcinoma,” is the second most common form of thyroid cancer, accounting for around 10 to 15 percent of all thyroid cancer cases. While its prognosis is not quite as positive as that of papillary thyroid cancer, the long-term survival rate is quite high. Young people with small lesions characteristic of follicular thyroid cancer have a 95 percent cure rate, according to the American Cancer Society.

Follicular carcinoma originates in the thyroid’s follicular cells, which produce the thyroid hormones critical for the body’s development and metabolism. Like other forms of thyroid cancer, follicular carcinoma is more common in females, striking women three times as often as men. Unlike other thyroid cancers, though, follicular thyroid carcinoma is most common among slightly older patients, ages 40 through 60.

A subset of follicular carcinoma, called “Hürthle cell carcinoma” or “oxyphil cell carcinoma,” accounts for about 4 percent of thyroid cancer cases, and has a less favorable prognosis than follicular thyroid carcinoma. This type of follicular cancer is harder to detect, and it isn’t as prone to absorbing radioactive iodine, which is often used to treat thyroid cancer.

Diagnosing Follicular Carcinoma

Sometimes, a definitive follicular thyroid cancer diagnosis can’t be made until treatment is underway. Pathologists need to examine the entire capsule around the suspicious thyroid nodule for the signs of invasion characteristic of follicular or Hürthle cell cancer, and the only way to microscopically examine the capsule is with surgery.

Treating Follicular Thyroid Cancer

Surgery is often the first line of recommended treatment for follicular carcinoma. Disagreement abounds in the medical community regarding how much of the thyroid should be removed, however. Since the surgery is in some ways diagnostic, some surgeons advocate for a partial removal, while others argue for a total thyroidectomy.

Follow-up after surgery often involves treatment with radioactive iodine, used to destroy any remaining cancer cells. Even though thyroid cells are the only ones in the body that absorb iodine — important for successful treatment — follicular cancer cells (especially in older people) are less likely to absorb the iodine.

In some cases, external beam radiation therapy is used to target cancer cells that can’t be removed through surgery or controlled with radioactive iodine.

Prognosis for Follicular Thyroid Carcinoma

To keep metabolic functions on an even keel following thyroid surgery and to discourage further cancerous cell growth, treatment with thyroid hormones is common for those who have had follicular thyroid cancer. Regular check-ups and chest x-rays are an important aspect of follow-up care.

Patients over 40 tend to develop an aggressive form of the disease, so the prognosis for this age group is not as good as it is for younger patients. Unlike papillary thyroid cancer, follicular carcinoma rarely spreads into surrounding lymph nodes, but it frequently invades the veins and arteries within the thyroid gland. The extent of this vascular invasion and possible hematogenous spread has a significant effect on long-term survival.

Resources

Norman, J. (2010). Thyroid cancer: Follicular cancer the second most common thyroid cancer. Retrieved March 23, 2010, from the Endocrineweb.com Web site: http://www.endocrineweb.com/cafol.html.

Thyroid Center Staff. (n.d.). Thyroid cancer follicular. Retrieved March 23, 2010, from the Columbia University Medical Center Web site: http://www.cumc.columbia.edu/dept/thyroid/follicular.html.

MedicineNet.com Staff. (n.d.). Thyroid cancer. Retrieved March 23, 2010, from the MedicineNet.com Web site: http://www.medicinenet.com/thyroid_cancer/article.htm.

American Cancer Society Staff. (n.d.). What is thyroid cancer? Retrieved March 23, 2010, from the American Cancer Society Web site: http://www.cancer.org/docroot/CRI/content /CRI_2_4_1X_What_is_thyroid_cancer_43.asp?sitearea=.