There are different types of thyroid cancer, which include papillary, follicular, medullary, anaplastic, and oncocytic.
Types of thyroid cancer can develop, grow, and spread in different ways, which can affect the treatment and outlook.
This article looks at the prevalence, symptoms, diagnosis, treatment, and outlook for each type of thyroid cancer.
Differentiated thyroid cancer includes papillary, follicular, and oncocytic thyroid cancer.
When examined under a microscope, differentiated thyroid cancer cells look similar to normal thyroid cells. In contrast, undifferentiated thyroid cancer cells look different.
In
Papillary thyroid cancer
The
Papillary thyroid cancer usually forms in one lobe of the thyroid gland and is generally very slow-growing. In some cases, papillary thyroid cancer may spread to lymph nodes in the neck, but it is usually still highly treatable.
Some variants of papillary cancer may grow and spread at a faster rate and may require more intensive treatment. These variants include:
- follicular
- tall cell
- columnar
- insular
- clear cell
- trabecular
- hobnail
- diffuse sclerosing
Follicular
Follicular thyroid cancer is the
It is less common for follicular thyroid cancer to spread to the lymph nodes, but it may spread to more distant areas of the body, such as the lungs or bones. In most cases, follicular thyroid cancer has a good outlook.
Oncocytic cell (Hürthle cell)
Oncocytic, or Hürthle cell, thyroid cancer is a rare type that accounts for around
Oncocytic thyroid cancer is more common in females and in people between the ages of 50 and 60 years. Oncocytic thyroid cancer is more common in specific populations that have high rates of iodine deficiency or enlarged thyroid glands.
Oncocytic thyroid cancer can be more aggressive than other types of thyroid cancer and may spread to other areas of the body. The overall 5-year relative survival rate for oncocytic thyroid cancer is still high, though.
Medullary thyroid cancer (MTC) is a rare type of thyroid cancer, accounting for around 1% to 2% of thyroid cancers in the United States.
MTC develops in C cells in the thyroid gland. C cells produce calcitonin, a hormone that helps control calcium levels in the blood.
The
- Sporadic MTC: Around 3 out of 4 cases of MTC are sporadic. People do not inherit sporadic MTC and do not have the genetic mutation seen with familial MTC. Sporadic MTC generally affects only one lobe of the thyroid gland, and usually occurs in older adults.
- Familial MTC: Around 1 in 4 cases of MTC are familial. People inherit familial MTC, which usually develops in childhood or early adulthood. Familial MTC usually affects both lobes of the thyroid gland and can spread early in its development.
The outlook for MTC is generally not as positive as papillary or follicular thyroid cancer, but MTC usually progresses slowly, and early detection and surgical treatment may cure it.
Anaplastic, or undifferentiated, thyroid cancer accounts for around
Anaplastic thyroid cancer can be challenging to treat and can spread quickly to the neck and other areas of the body.
Symptoms of thyroid cancer include:
- swelling in the neck
- a lump, or nodule, at the front or side of the neck, which may grow quickly depending on the type of thyroid cancer
- feeling pain in the front of the neck, which may spread to the ears
- persistent voice changes, such as hoarseness
- difficulty swallowing or breathing
- constant cough
Symptoms can vary for different types of thyroid cancer. For papillary and follicular thyroid cancer, the most common symptom is a painless lump in the neck that may slowly get bigger. Oncocytic thyroid cancer has
The most common symptom of MTC is a lump in the neck, which may feel painful. The most common symptom of anaplastic thyroid cancer is a fast-growing lump in the neck.
Many symptoms of thyroid cancer can occur for other, often benign, reasons, but it is important to contact a doctor as soon as possible if people notice any of the above symptoms.
Biopsies can help doctors diagnose the type of thyroid cancer. A biopsy removes a tissue sample to examine for cancer cells and
- Fine needle aspiration (FNA): A doctor will use a thin, hollow needle to extract cells from a thyroid nodule or swollen lymph nodes for laboratory examination.
- Core biopsy: A core biopsy uses a larger needle to get a bigger sample containing more cells for examination.
- Lobectomy: A lobectomy is a surgical procedure to remove half of the thyroid gland.
Further tests can also help diagnose specific types of thyroid cancer. If a biopsy suggests a person has MTC, a doctor may take blood tests to measure certain hormones and proteins, such as calcitonin, which are usually higher in people with MTC.
Thyroid cancer treatment depends on the type and stage of the cancer, and
- Papillary, follicular, and oncocytic: In most cases, treatment involves surgery to remove the whole thyroid gland, or sometimes only the side containing the cancer. Surgery will also remove any affected lymph nodes.
- MTC: The main treatment for MTC is total thyroidectomy to remove the entire thyroid gland, as well as removal of nearby lymph nodes. For advanced MTC, people may also have radiation therapy, targeted therapy, or chemotherapy.
- Anaplastic: Doctors may use surgery to remove cancerous areas, although this can be more challenging with anaplastic thyroid cancer. Doctors may also use external beam radiation, chemotherapy, or targeted therapy.
Removal of the thyroid gland means people will need to take thyroid hormone therapy following treatment.
The
| Stages | Papillary | Follicular | Medullary | Anaplastic |
|---|---|---|---|---|
| Localized | >99.5% | >99.5% | >99.5% | 39% |
| Regional | 99% | 98% | 92% | 11% |
| Distant | 74% | 67% | 43% | 4% |
| All stages combined | >99.5% | 98% | 91% | 8% |
The 10-year survival rate for oncocytic thyroid cancer can be above
Most thyroid cancers are differentiated types, including papillary, follicular, and oncocytic. Differentiated thyroid cancers have cancer cells that look similar to normal thyroid cells. Other types are less common and include medullary and anaplastic thyroid cancer.
Treatment can depend on the type of thyroid cancer, but may include surgery to remove part or all of the thyroid gland. In some cases, treatment may cure thyroid cancer.