About Merkel Cell Carcinoma

Overview
Merkel Cell Carcinoma (MCC) is a rare and aggressive type of skin cancer that originates from Merkel cells in the skin. These cancer cells grow uncontrollably, often appearing as a single reddish or purple lump on sun-exposed areas like the face, neck, or arms. Unlike more common skin cancers, MCC starts in Merkel cells and can spread rapidly to other parts of the body. It is considered rare compared to other skin cancers, with around 1,500 cases diagnosed each year in the United States.
Causes and Risk Factors

Non-modifiable risk factors for MCC are factors that cannot be changed. These include:

  • Age: Being older than 50 years
  • Ethnicity: Fair-skinned, and being of Caucasian descent
  • Weakened immune system: Having a weakened immune system due to diseases like chronic lymphocytic leukemia or HIV infection can also contribute to its development.
  • Having a history of other types of cancer can increase the risk of developing MCC

Modifiable risk factors for MCC are factors that can be changed or influenced. These include:

  • Excessive sun exposure, either from natural sunlight or artificial sources, such as tanning
  • Taking immunosuppressive drugs after an organ transplant beds.
Symptoms

MCC often begins with a noticeable lump or nodule on the skin. Other symptoms include:

  • Single Lump/Nodule: Often the first sign, this lump is typically firm, red or violet, fast-growing, and painless.
  • Location: Commonly appears on sun-exposed areas, such as the face, neck, or arms, but can develop anywhere on the body.
  • Lymph Node Spread: If MCC spreads, it may cause visible lumps under the skin near lymph nodes.

In later stages, additional signs may include:

  • Abnormal nodules or raised bumps
  • Irregularly shaped moles
  • Rough patches of red, pink, brown, or blue skin

A biopsy is essential for a definitive diagnosis, as MCC can mimic other skin conditions.

Diagnosis

To diagnose MCC, doctors commonly perform the following examinations, tests, and procedures:

  • Physical exam: Doctors may detect MCC during a physical exam by checking for lumps, lesions, or irregularly shaped moles on the skin.
  • Skin biopsy: If any abnormalities are found during the physical exam, a skin biopsy is performed. In this procedure, a small amount of the lump is removed and examined under a microscope to check for cancer cells.

To determine the stage or severity of MCC, additional examinations, tests, and procedures may be conducted:

  • Sentinel lymph node biopsy: This test helps to find out if the cancer has spread to the lymph nodes.
  • Imaging tests: Various imaging tests such as X-rays, positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT) scans may be used to determine the extent of cancer spread in the body. These tests provide detailed pictures of areas inside the body from different angles and help in staging MCC.
Treatment Options

The goals of treating MCC include removing the cancer, preventing its spread, and improving quality of life.

  • Medication types for treatment may involve immunotherapy using drugs like avelumab, pembrolizumab, nivolumab, or ipilimumab to boost the body's immune response against cancer cells.
  • Therapeutic procedures such as surgery aim to remove tumors and affected tissues, while radiation therapy targets cancer cells with high-energy rays to stop their growth.
  • Lifestyle behavior changes like maintaining a healthy diet, regular exercise, and avoiding harmful habits such as smoking can support overall treatment effectiveness.
  • Other treatments like chemotherapy may be used to kill cancer cells throughout the body, especially in advanced stages of MCC.
  • Clinical trials offer innovative approaches to treatment and may provide access to new therapies that can potentially improve outcomes for individuals with MCC.
Progression or Complications

Merkel Cell Carcinoma typically progresses rapidly, with early metastasis to other parts of the body like the lymph nodes, brain, and lungs. This aggressive cancer can be challenging to treat once it has spread.

Common complications of Merkel cell carcinoma (MCC) include:

  • Metastasis: MCC can spread to distant parts of the body, which often lowers survival rates.
  • Local Recurrence: The cancer may return in the original location, which is more common than distant metastasis.

These complications highlight the importance of early detection and regular monitoring for MCC.