Home > Health A – Z > Thyroid Cancer

Thyroid Cancer

Cancer that forms in the thyroid gland (an organ at the base of the throat that makes hormones that help control heart rate, blood pressure, body temperature, and weight).

PubMed Health Glossary
(Source: NIH - National Cancer Institute)

About Thyroid Cancer

Thyroid cancer is a disease in which malignant (cancer) cells form in the tissues of the thyroid gland.

The thyroid is a gland at the base of the throat near the trachea (windpipe). It is shaped like a butterfly, with a right lobe and a left lobe. The isthmus, a thin piece of tissue, connects the two lobes. A healthy thyroid is a little larger than a quarter. It usually cannot be felt through the skin.

The thyroid uses iodine, a mineral found in some foods and in iodized salt, to help make several hormones. Thyroid hormones do the following:

Read more about Thyroid Cancer

What works? Research summarized

Evidence reviews

Use of color Doppler ultrasonography for the prediction of malignancy in follicular thyroid neoplasms: systematic review and meta-analysis

This review concluded that predominant internal flow seen on colour Doppler ultrasound was associated with malignancy of thyroid follicular neoplasms; absence of internal flow or predominantly peripheral flow indicated low probability of malignancy. The small number and relatively poor quality of included studies and lack of reporting of analytical methods mean that these conclusions should be interpreted cautiously.

Utility of positron emission tomography with fluorodeoxyglucose (FDG-PET) in the evaluation of thyroid cancer: a systematic review

After the initial thyroid cancer treatment, the detection of likely recurrences and/or metastases is made through the measurement of serum markers determinations and diagnostic image procedures. These techniques may be negative in spite of biochemical evidence of metastatic disease. The positron emission tomography with fluorodeoxyglucose (FDG-PET) has been proposed as an accurate method to detect it. The aim of this study is to present a synthesis of the evidences obtained from a systematic review regarding FDG-PET accuracy in locating suspected metastases of previously treated thyroid cancer, when the conventional methods failed to do it. A bibliographic review of all studies related to FDG-PET and differentiated thyroid cancer was made on MEDLINE, indexed until September 2005. Two hundred and sixteen citations were collected and 17 studies included, 71% were published after 2000. FDG-PET sensibility was high, with only one study presenting a sensibility lower than 75%. The specificity, examined in 12 studies was lower than 75% in 3 studies. There was at least one test compared to FDG-PET in 41% of the studies. The results point to FDG-PET as a useful diagnostic test to detect and localize thyroid cancer metastases, with direct implications in the treatment of these patients.

Venous Thromboembolism: Reducing the Risk of Venous Thromboembolism (Deep Vein Thrombosis and Pulmonary Embolism) in Patients Admitted to Hospital

Venous thromboembolism (VTE) is a term used to include the formation of a blood clot (a thrombus) in a vein which may dislodge from its site of origin to travel in the blood, a phenomenon called embolism. A thrombus most commonly occurs in the deep veins of the legs; this is called deep vein thrombosis. A dislodged thrombus that travels to the lungs is known as a pulmonary embolism.

See all (230)

Summaries for consumers

Thyroid Cancer Treatment (PDQ®): Patient Version

Expert-reviewed information summary about the treatment of thyroid cancer.

Angiogenesis‐inhibitors for metastatic thyroid cancer

There is currently no reliable evidence from randomized controlled trials demonstrating that the benefits of angiogenesis‐inhibitors outweigh their risks in treating advanced thyroid cancer. Angiogenesis (that is blood supply of tumors and new blood vessel formation in tumors) plays an important role in tumor growth and metastasis. Currently, four randomized controlled trials are ongoing. Despite the potential benefits of angiogenesis‐inhibitors, various undesirable side effects have been reported. These include rash, diarrhea, fatigue, nausea, proteinuria, stomatitis or mucositis, and hypertension. We will update this review as data from the ongoing trial become available.

Amifostine for salivary glands in high‐dose radioactive iodine treated differentiated thyroid cancer

Thyroid cancer is the most common malignancy of the endocrine system consisting of several subtypes like papillary carcinoma (accounting for 80% of cases) and follicular carcinoma (accounting for 11% of cases). These are collectively referred to as 'differentiated thyroid cancer'. Treatment with radioactive iodine after surgery (ablation of the thyroid gland or 'thyroidectomy') is important for the detection of metastatic disease and for the destruction of the remaining thyroid tissue with microscopic cancer. After radioactive iodine treatment, adverse effects may happen in the salivary glands and cause salivary gland swelling and pain, usually involving the parotid. The symptoms may develop immediately after a therapeutic dose of radioactive iodine or months later and progress in intensity with time. Secondary complications reported include dry mouth ('xerostomia') and taste alterations.

See all (43)

Terms to know

Blood Pressure
The force of blood exerted on the inside walls of blood vessels. Blood pressure is expressed as two numbers. For example, a blood pressure result of 120/80 is said as "120 over 80."
A mineral needed for healthy teeth, bones, and other body tissues. It is the most common mineral in the body. A deposit of calcium in body tissues, such as breast tissue, may be a sign of disease.
A narrow part inside the body that connects two larger structures.
Larynx (Voice Box)
The area of the throat containing the vocal cords and used for breathing, swallowing, and talking. Also called voice box.
Parathyroid Glands
One of four pea-sized glands found on the surface of the thyroid. The parathyroid hormone made by these glands increases the calcium level in the blood.
Thyroid Gland
A gland located beneath the larynx (voice box) that makes thyroid hormone and calcitonin. The thyroid helps regulate growth and metabolism. Also called thyroid gland.
Thyroid Hormones
A hormone that affects heart rate, blood pressure, body temperature, and weight. Thyroid hormone is made by the thyroid gland and can also be made in the laboratory.
Trachea (Windpipe)
The airway that leads from the larynx (voice box) to the bronchi (large airways that lead to the lungs). Also called windpipe.

More about Thyroid Cancer

Photo of an adult

Also called: Malignant tumour of the thyroid gland, Malignant tumor of the thyroid gland

Other terms to know: See all 8
Blood Pressure, Calcium, Isthmus

Related articles:
Information for Health Professionals
Cancer: Anxiety and Distress

Keep up with systematic reviews on Thyroid Cancer:


PubMed Health Blog...

read all...