What is Thyroid Cancer?

Thyroid cancer is a malignancy of the thyroid gland. It happens when there is an abnormal, invasive growth of mutated, abnormal thyroid cells. Thyroid cancer is usually a very slow-growing cancer, which means it is usually confined to the thyroid gland, or possibly the surrounding lymph nodes when it is discovered.

The most common type, which accounts for 90-95% of thyroid cancer is papillary thyroid cancer.

Most types of thyroid cancer are very treatable and patients go on to live long, healthy, normal lives.

The only risk factors for thyroid cancer are a history of radiation to the head and neck and a personal or family history of an endocrine tumor syndrome, specifically Multiple Endocrine Neoplasia types 2A and 2B. Thyroid cancer can rarely be a part of other cancer syndromes.

An illustration showing thyroid cancer

What are the symptoms of thyroid cancer?

Most thyroid cancers do not produce any symptoms. However, if large enough in size (and this is different for everyone), it may cause:

  • Pressure in the front of the neck
  • Difficult or uncomfortable swallowing
  • Problems breathing when lying flat
  • A new persistent cough
  • Visible protrusion in the neck
  • More advanced cancers may rarely also cause a permanent change in your voice

How is Thyroid Cancer diagnosed?

All suspicious thyroid nodules should be evaluated with a dedicated neck ultrasound that includes the lymph nodes in lateral neck and a fine needle biopsy. Some types of thyroid cancer can be diagnosed with a biopsy whereas others may be read as ‘indeterminate’ on biopsy and require surgical removal for a definitive diagnosis.

More advanced thyroid cancers (when growing into other neck structures) should have a neck CT before surgery to help with operative planning.

Learn About Symptoms, Diagnosis and Treatment Options

Watch these videos of Dr. Melanie Goldfarb, endocrine surgeon and Director of the Center for Endocrine Tumors and Disorders explaining symptoms, diagnosis, and treatment options for thyroid cancer.

Symptoms, Diagnosis and Types of Thyroid Cancer
Learn About Symptoms & Diagnosis
Thyroid Cancer Treatment
Learn About Treatments



Thyroid Cancer Treatments

Historically, there were 3 components to thyroid cancer treatment: surgery, radioactive iodine, and thyroid hormone suppression. However, the paradigm for thyroid cancer treatment has shifted and a more conservative approach is favored for most patients.


Most patients should undergo thyroid surgery to remove the thyroid cancer. The extent of your surgery (thyroid lobectomy vs total thyroidectomy) will depend on the size of your cancer, if the thyroid cancer is extending outside of the thyroid gland, and if you have nodules in your other thyroid lobe.

Radioactive iodine

After a total thyroidectomy, some intermediate-high risk patients with more aggressive cancers (not medullary) will be recommended to additional treatment with radioactive iodine.

Active Surveillance

This strategy is being offered to select patients (mostly ‘older’) with small, 1cm or less tumors. Saint Johns does have an active surveillance program and if you think you may be a candidate, you can discuss with your doctor. Contact us to schedule an appointment.

Thyroid hormone replacement

All thyroid cancer patients that have had a total thyroidectomy will be put on brand name thyroid medication. Very high risk patients will be given larger, suppressive doses of thyroid hormone replacement. This will help prevent any remaining thyroid tissue or cells from growing back at all or in the form of cancer. Your TSH levels will be monitored by your endocrinologists to obtain your optimum dose.


Different Types of Thyroid Cancer

Papillary thyroid cancer (PTC)

PTC is the most common type of thyroid cancer.
Garden variety papillary cancer is usually very slow growing and can be removed surgically. Though the cancer often metastasizes to the surrounding lymph nodes, this generally does not affect prognosis and most patients do very well.

Follicular (FTC) and Hurthle cell thyroid cancer

Follicular (FTC) and Hurthle cell thyroid cancer are two different types of cancer but discussed together make up 5-10% of all cancers.
The only way to have a definitive diagnosis for these types of thyroid cancers is to remove the nodule and examine the capsule under the microscope for invasion. Follicular thyroid cancer tends to spread through the bloodstream to the lungs and bone and not to the lymph nodes. Hurthle Cell thyroid cancer can spread to either the lymph nodes or organs. It is slightly more aggressive than PTC.

Medullary thyroid cancer

Rare (3-10%) type of thyroid cancer.
This is the type of thyroid cancer in patients with hereditary endocrine tumor syndromes and is more aggressive than PTC and FTC. Surgery is the only form of treatment, so a good first operation is important. All patients should have a total thyroidectomy (their entire thyroid removed) as part of their treatment.

Anaplastic thyroid cancer

Accounts for about 1% of all thyroid cancers and is the most aggressive type of thyroid cancer.
It usually occurs in older patients that present with a very rapidly growing hard neck mass and has a poor prognosis.

‘Premalignant’ or self-contained thyroid cancer types

  • NIFTP – Noninvasive Follicular Variant of Papillary thyroid cancer: this is a newer classification. These tumors still need to be removed surgically, but as the ‘cancer’ has not yet spread, a limited surgical approach (thyroid lobectomy with no additional treatment is more than sufficient.
  • Minimally Invasive FTC: can be thought of as a ‘contained’ FTC. These tumors still need to be removed surgically, but as the ‘cancer’ has not yet spread, a limited surgical approach (thyroid lobectomy with no additional treatment is more than sufficient.

Thyroid Cancer Prognosis