What Causes a Thyroid Tumor in Adults?

The United States sees approximately 20,000 new cases of thyroid cancer each year. Despite the scary prospect of such a diagnosis, tumors of the thyroid are treated with relative ease. Although certain conditions lend themselves to development of the disease, the exact cause is something of a mystery.

Nodules

• According to the American Thyroid Association (ATA), a thyroid nodule is any abnormal growth of thyroid cells that form into a lump within the thyroid. It is the most common endocrine problem in the United States. Most are benign---non-cancerous---but around 5 percent do contain cancerous cells. Thyroid nodules can be either solid or filled with fluid (thyroid cysts) and usually are discovered during a routine physical exam.

Risk Groups

• Although the American Association of Clinical Endocrinologists reports than 80 percent of those who suffer from thyroid disorders are female, it is men who are most likely to face thyroid cancer. Other risk factors include being younger than 30 or older than 60, a family history of thyroid or endocrine cancers, and having had head or neck radiation. Cancerous nodules often are large and hard, causing significant discomfort and neck pain.

Causes

• Physicians at the Mayo Clinic say it is not known specifically what causes a thyroid tumor in adults. But the process of cancer growth is clear. "Thyroid cancer occurs when cells in your thyroid undergo genetic changes (mutations). The mutations allow the cells to grow and multiply rapidly. The cells also lose the ability to die, as normal cells would. The accumulating abnormal thyroid cells form a tumor," the Mayo Clinic website says.

  People exposed to radiation, especially as children, are much more susceptible to developing thyroid cancer, the ATA reports. Unbelievably, even as late as the 1940s and 1950s, X-rays were used as a treatment for acne, swollen tonsils, adenoids, lymph nodes and even to measure foot size in shoe stores. Those exposed to such radiation have a much higher likelihood of developing a thyroid tumor as adults. Some naturopathic medical practitioners attribute thyroid cancers to an increase in human intake of chemicals and pesticides prevalent in foods, water and air.

Types

• According to the Mayo Clinic, papillary thyroid cancer is the most common, comprising nearly 80 percent of all diagnoses. It may occur at any age but patients are typically between 30 and 50. Follicular thyroid cancer---which includes Hurthle cell cancer---occurs most often in those above 50 years of age. Medullary thyroid cancer may be linked to inherited genetic syndromes; in other cases, it is referred to as "sporadic." Anaplastic thyroid cancer is extremely rare, but very aggressive, and typically occurs in those above the age of 60. The also rare thyroid lymphoma, whose victims are usually over 70, originates in the immune system cells of the thyroid.

Symptoms

• Signs of thyroid cancer usually do not appear early in the disease but make themselves known only when it has progressed significantly, reports the ATA. Symptoms include a noticeable lump felt by fingers above the thyroid, changes to the voice and hoarseness, difficulty swallowing, neck pain and swollen lymph nodes in the neck.