Papillary thyroid cancer is one of the most common and slow growing types of thyroid cancer.

The thyroid is a small, hormone-producing gland in the neck. It plays a crucial role in regulating your body’s metabolism, growth, and development.

When thyroid cells mutate and begin to grow and divide uncontrollably, cancer can develop in the thyroid gland.

The most common type of thyroid cancer is papillary thyroid cancer, so named for its distinctive papillae, or finger-like projections, when viewed under a microscope.

Papillary thyroid cancer is the most common type of thyroid cancer. It accounts for about 88% of all thyroid cancer cases.

Papillary thyroid cancer typically develops from the follicular cells of the thyroid gland. It is characterized by its small, finger-like projections called papillae.

Papillary thyroid cancer tends to be less aggressive and less likely to spread beyond the thyroid gland than other types of thyroid cancer.

While it may spread to nearby lymph nodes, papillary thyroid cancer typically doesn’t spread to distant organs, such as the lungs or bones.

Papillary thyroid cancer is typically slow growing. It often doesn’t cause any symptoms in its early stages. Doctors often discover it incidentally during a routine medical examination or imaging test.

However, as the cancer grows, papillary thyroid cancer may cause the following symptoms:

  • Painless lump or swelling in the neck: This is the most common symptom of papillary thyroid cancer. The lump or swelling is usually located in the front of the neck, just below the Adam’s apple.
  • Enlarged lymph nodes: Papillary thyroid cancer can spread to nearby lymph nodes, causing them to enlarge and become tender.
  • Hoarseness or difficulty speaking: Papillary thyroid cancer can affect the nerves that control the vocal cords, causing hoarseness or difficulty speaking.
  • Difficulty swallowing: As the tumor grows, it may press on the esophagus or trachea, causing difficulty swallowing or breathing.
  • Neck pain: Papillary thyroid cancer can cause pain or discomfort in the neck, especially if the tumor is large or has spread to nearby tissues.

Most cases of papillary thyroid cancer are classified as classic papillary thyroid cancer, but several subtypes can be differentiated based on their microscopic features.

Factors such as environmental exposure, radiation exposure, and genetics can contribute to these differences.

Here’s a general breakdown of the types of papillary thyroid cancer:

  • Classic papillary thyroid cancer: This is the most common subtype of papillary thyroid cancer. It accounts for about 55–65% of cases. It’s characterized by finger-like extensions of cancer cells into the thyroid gland.
  • Follicular variant papillary thyroid cancer: This subtype is characterized by the presence of follicular cells, which are arranged in a pattern similar to follicular thyroid cancer. Follicular variant papillary thyroid cancer accounts for about 23–41% of papillary thyroid cancers.
  • Tall cell variant papillary thyroid cancer: This subtype of papillary thyroid cancer is characterized by elongated, or tall, cells. It tends to be more aggressive than classic papillary thyroid cancer.
  • Diffuse sclerosing variant papillary thyroid cancer: This fairly rare subtype tends to affect younger people. Its cancer cells typically spread throughout the thyroid gland, giving the gland a hard, rubbery consistency.
  • Warthin-like variant papillary thyroid cancer: This relatively rare subtype of papillary thyroid cancer is characterized by lymphoid tissue within the tumor. It’s named after a similar-looking tumor that can occur in the salivary gland called Warthin tumor, although the two tumors are unrelated.
  • Columnar cell variant papillary thyroid cancer: This relatively uncommon subtype is characterized by tall, column-shaped cells within the tumor. These cells are elongated and have a distinctive appearance that sets them apart from the typical papillary thyroid cancer cells.

The exact cause of papillary thyroid cancer is not fully understood, but doctors believe a combination of genetic and environmental factors causes it.

According to the American Cancer Society, DNA mutations may play a significant role in the development of papillary thyroid cancer. Mutations in genes such as BRAF, RET, and RAS are commonly found in papillary thyroid cancer cells. These mutations can lead to the uncontrolled growth and division of cells, which can eventually lead to cancer.

The American Cancer Society also notes that people who have been exposed to radiation, particularly during childhood, have an increased risk of developing papillary thyroid cancer.

Other risk factors for papillary thyroid cancer include:

  • a family history of thyroid cancer or other endocrine tumors
  • being female
  • having certain noncancerous thyroid conditions, such as goiter or thyroid nodules

Doctors typically diagnose papillary thyroid cancer through a combination of medical history, physical examination, and diagnostic tests.

During a physical examination, a doctor may feel for lumps or nodules on your thyroid gland and check for any swelling or enlargement. They may order blood tests to assess thyroid hormone levels.

The most common diagnostic test for papillary thyroid cancer is a fine-needle aspiration biopsy. During the procedure, a doctor removes a small sample of cells from the thyroid gland using a thin needle. The cells are then examined under a microscope and checked for cancer.

Imaging tests may also be used to determine the size and location of the tumor and to see whether the cancer has spread to other areas of the body. These tests may include:

The most widely used staging system for papillary thyroid cancer is the American Joint Committee on Cancer (AJCC) TNM system. It considers the size of the tumor, whether the cancer has spread to nearby lymph nodes, and whether the cancer has spread to other parts of the body.

The basic stages of papillary thyroid cancer include:

  • Stage 1: The tumor is confined to the thyroid gland and is 2 centimeters (cm) or smaller.
  • Stage 2: The tumor is larger than 2 cm but is still confined to the thyroid gland.
  • Stage 3: The tumor has spread to nearby lymph nodes or nearby structures, such as the windpipe (trachea) or swallowing tube (esophagus).
  • Stage 4: The tumor has spread to distant sites in the body, such as the lungs or bones.

This is a basic staging system for papillary thyroid cancer. The staging system is slightly different for people ages 55 and over.

Treatment for papillary thyroid cancer typically involves surgery to remove the affected thyroid gland, followed by radioactive iodine therapy to destroy any remaining cancer cells.

In some cases, thyroid hormone replacement therapy may be needed to replace the hormones that were produced by the removed thyroid gland.

What is the survival rate of papillary thyroid cancer?

With early detection and appropriate treatment, the outlook for people with papillary thyroid cancer is generally good. According to the American Cancer Society, the overall 5-year relative survival rate is over 99%.

Receiving a cancer diagnosis of any kind can be a frightening and confusing experience. It’s common to feel anxious, fearful, and uncertain about what the future may hold.

However, it’s important to remember that papillary thyroid cancer is generally treatable and often curable, especially when detected early.

Most people with papillary thyroid cancer lead healthy and productive lives after treatment.