The thyroid is a gland in the neck, in front of the trachea, or windpipe. It produces hormones that help regulate a person’s metabolism. Papillary thyroid cancer (PTC) is a type of cancer that develops on the thyroid gland.

The thyroid gland sits in the front of the lower neck. It is a butterfly-shaped organ that straddles the trachea.

PTC is the most commonly diagnosed type of thyroid cancer. A 2021 study reports that PTC makes up approximately 90% of all thyroid cancer cases.

It is a highly treatable cancer that grows slowly.

This article will look at what PTC is. It will also discuss the symptoms, stages, causes, treatment options, and outlook.

A person who may have papillary thyroid cancer lying on a medical table.Share on Pinterest
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PTC is a tumor that grows on the thyroid gland in the front of the neck.

The word “papillary” describes the way the cells of this particular cancer tumor grow. In a papillary tumor, cells stick together and form long strands of tissue.

PTCs grow slowly and often spread to the lymph nodes. However, even if they have spread, the American Cancer Society (ACS) notes that treatment is often successful and that the cancer is rarely fatal.

PTC can affect anyone. However, according to the National Organization for Rare Disorders, it is more likely to develop in people aged 30–50 years. It also affects females more so than males.

Although experts do not know what causes PTC, one risk factor is childhood exposure to radiation due to medical treatments or other environmental exposure.

Types

According to the ACS, the most common subtype of PTC is the follicular variant. This subtype is very similar to classical PTC in treatment and outcome.

A 2020 narrative review reports that the following are more aggressive types of PTC:

  • Diffuse sclerosing: This accounts for 6% of PTCs. The authors note that despite its aggressive behavior, the overall survival rate is similar to classic PTC.
  • Tall cell variant (TCV): Healthcare professionals characterize TCV by the tall cells that have a height that is three times their width. One study found that TCV accounts for approximately 1.3–13% of PTC cases in literature. It also affects those aged 41–66 years. TCV has a higher rate of recurrence and a shorter survival rate.
  • Columnar cell variant (CCV): This is a rare subtype and represents 0.15–0.2% of PTC cases. It has a fast growth rate and a high rate of recurrence.
  • Solid variant: This rare variant accounts for 3% of PTC cases. It has a poorer outlook compared with PTC. Healthcare professionals may diagnose solid variant if all or nearly all of the tumor is solid in appearance.
  • Hobnail variant: Experts characterize this variant by the presence of hobnail cells. This subtype has a 5-year survival rate of 69.1% and a 10-year survival rate of 64.1%.

It is important to note that this list is not exhaustive.

Many people with PTC will have no symptoms.

However, if symptoms do appear, a person may experience:

According to the National Cancer Institute (NCI), the staging of PTC is different for people over and under the age of 55 years and varies depending on how far the cancer has spread.

For people under the age of 55 years, the staging is as follows:

  • Stage 1: This includes any tumor at any size that has or has not spread to the lymph nodes. It has not spread to other parts of the body.
  • Stage 2: This includes any tumor at any size that has spread to the nearby lymph nodes and tissues. It has also spread to other parts of the body.

The staging for people over the age of 55 years is the following:

  • Stage 1: The cancer is present in the thyroid and measures 4 centimeters (cm) or less.
  • Stage 2: This can involve one of the following:
    • The cancer is in the thyroid and measures 4 cm or less. Also, it has spread to the lymph nodes nearby.
    • The cancer is in the thyroid, measuring 4 cm or more. It may have spread to the lymph nodes nearby.
    • The cancer is any size. It has spread to nearby muscles in the neck. It may have also spread to the nearby lymph nodes.
  • Stage 3: The tumor is any size and has spread to the soft tissues underneath the skin, esophagus, windpipe, larynx, or laryngeal nerve. It may have also spread to the lymph nodes nearby.
  • Stage 4A: The tumor is any size and has spread to tissues in front of the spine. It may have surrounded the carotid artery and the blood vessels that are between the lungs. It may have spread to the lymph nodes.
  • Stage 4B: The tumor is any size. The cancer has spread to the lungs or bones and perhaps the lymph nodes.
  • Recurrent: This includes any cancer that has returned following treatment.

Experts do not know the exact cause of PTC. However, high-dose external radiation can increase a person’s risk of developing it.

This might be due to medical treatments during childhood or environmental exposure, such as a nuclear accident.

Radiation that a person receives intravenously as part of medical testing or treatment does not increase their risk of developing PTC.

Certain hereditary conditions can also increase the likelihood of PTC, including:

  • Familial adenomatous polyposis (FAP): FAP develops due to APC gene mutations.
  • Cowden disease: This condition occurs due to defects in the PTEN gene.
  • Carney complex, type 1: This occurs due to PRKAR1A gene mutations.

Moreover, females — particularly those aged 30–50 years — receive a PTC diagnosis more commonly than males.

If a person feels or sees a lump in the front of their neck, has difficulty swallowing, or feels enlarged lymph nodes in their neck that do not return to normal size, they should contact a healthcare professional.

A doctor will perform a physical examination by feeling the thyroid gland in the neck and surrounding lymph nodes for anything unusual.

They may also order one or more tests to check for PTC:

  • Laryngoscopy: A doctor will examine the larynx using a thin, tube-like instrument.
  • Blood hormone study: They will check a blood sample to measure the hormone levels. A higher amount can indicate the presence of a condition affecting the organ that makes the hormone. They may also check the levels of thyroid-stimulating hormone (TSH). TSH, which the pituitary gland produces, stimulates the release of the thyroid hormone.
  • Blood chemistry: They will check a blood sample to measure substances such as calcium.
  • Imaging tests: They may order an ultrasound or CT scan.
  • Biopsy: A doctor may remove a part of the thyroid tissue using a thin needle. Alternatively, they may perform a surgical biopsy. During this procedure, they will remove the thyroid nodule or a lobe of the thyroid. A biopsy or tissue sampling can help determine the type of the cancer cells and whether the condition is benign.

Based on their findings, the doctor will work with the person to design the most suitable treatment plan.

If a healthcare professional diagnoses PTC, they may recommend one of six types of treatment:

  • Surgery: Surgery is the most common form of treatment. This is to remove the tumor and any tissue that it has spread to. A surgeon will perform a thyroidectomy, which is the removal of the thyroid, or a lobectomy, which is the removal of a part of the thyroid.
  • Radioactive iodine: This uses high-energy X-rays to kill cancer cells.
  • Chemotherapy: This uses drugs to prohibit the growth of cancer cells.
  • Thyroid hormone therapy: This type of therapy removes hormones or blocks their activity, which stops cancer cells from growing. In this case, the drugs can stop the body from producing thyroid-stimulating hormones.
  • Targeted therapy: This uses medication to identify and attack cancer cells.
  • Watchful waiting: A healthcare professional will closely monitor a person’s condition until symptoms appear or change.

The thyroid gland produces important hormones that control many bodily functions. These hormones are triiodothyronine and thyroxine.

The United Kingdom’s National Health Service (NHS) notes that after a thyroidectomy, a person will experience symptoms of an underactive thyroid, or hypothyroidism. Symptoms include:

If a surgeon removes a portion of or the entire thyroid, a person will need to start taking triiodothyronine and thyroxine in the form of a pill. They will need to continue this for the rest of their life. Otherwise, they may experience the symptoms of hypothyroidism.

They will also need to get blood tests every 3–6 months to monitor their thyroid hormone levels.

According to the ACS, most people who develop thyroid cancer have no known risks. As a result, it is not possible to prevent PTC.

Radiation exposure increases the risk of developing thyroid cancers. Doctors no longer use radiation to treat less serious conditions in children, and it is unclear to what extent X-rays and CT scans expose people to radiation.

Healthcare professionals will not use these tests in children unless absolutely necessary, and when they do, they will use the lowest dose of radiation possible.

Additionally, maintaining a moderate body weight can help reduce the risk of developing PTC.

Authors of a 2018 review conclude that although the outlook for PTC is excellent, up to 20% of people develop recurrent PTC.

The average time of recurrence can range from 6 months to decades.

The risk factors for recurrence are the following:

  • the size of the tumor
  • being male
  • receiving a PTC diagnosis at the age of over 45 years
  • the cancer spreading outside the thyroid into the surrounding areas
  • the cancer spreading outside the lymph nodes

A relative survival rate helps give an idea of how long a person with a particular condition will live after receiving a diagnosis compared with those without the condition.

For example, if the 5-year relative survival rate is 70%, it means that a person with the condition is 70% as likely to live for 5 years as someone without the condition.

It is important to remember that these figures are estimates. A person can consult a healthcare professional about how their condition is going to affect them.

According to the ACS, the 5-year relative survival rates for PTC are as follows:

Type of PTCSurvival rate
localized, meaning the cancer has not spread beyond the lymph nodenearly 100%
regional, which means the cancer has spread to nearby structures99%
distant, meaning cancer has reached other parts of the body76%
all stages combinednearly 100%

The following can affect the outlook and treatment options:

  • the person’s age
  • the stage of the cancer
  • whether a surgeon completely removed the cancer
  • the person’s general health
  • whether the cancer has returned

Finding support while undergoing treatment for cancer can be an important step.

A few organizations that can help include:

A person should contact a healthcare professional if they notice a lump in their neck or if their lymph nodes become enlarged and firm and do not return to their normal size.

If a person notices any symptoms of PTC, they should seek medical attention.

PTC is a common and highly curable cancer that generally occurs in females more often than in males.

People with PTC usually have no symptoms but may notice a lump in the neck or have trouble swallowing. They may also notice enlarged lymph nodes that do not subside on their own.

This type of cancer often develops after exposure to high levels of radiation in childhood or an environmental exposure, such as a nuclear accident.

Anyone who notices enlarged lymph nodes in the neck or a lump in or on the neck should consult a doctor.