Merkel Cell Carcinoma

Merkel cell carcinoma is a rare type of aggressive skin cancer with a high risk of recurrence and metastasis, often within two to three years of initial diagnosis. The cancer affects the skin's outer layer, the epidermis, and can be life-threatening. It often spreads easily to the lymph nodes and other organs. Age, viral infections, increased sun exposure, and a compromised immune system may cause Merkel cell carcinoma. Doctors usually treat the condition through surgical removal, but the tumor may often return. 

We will explore everything about Merkel cell carcinoma to keep you well-informed about the condition and help determine when to seek medical help. 

What is Merkel Cell Carcinoma?

Merkel cell carcinoma, also known as neuroendocrine carcinoma, is a rare type of skin cancer that affects older people. This rare, life-threatening cancer begins at the Merkel cells found in the superficial layer of the skin, known as the epidermis. Merkel's cells are present near the nerve endings and are thus responsible for touch. Substances present in them that act like hormones also give them endocrine functions. 

What Are the Stages of Merkel Cell Carcinoma?

The cancer stage describes how much the cancer has spread in your body. It helps determine how serious the cancer is and how to treat it. Merkel cell carcinoma is divided into the following stages, namely:

Stage 0

• This stage is known as carcinoma in situ since it is present only in the superficial skin layer.
• The tumor has not spread to the lymph nodes and other distant organs. 

Stage I

• The cancer is not more than 2 cm in diameter. 
• It has not spread to the lymph nodes or distant organs. 

Stage IIA

• The cancer is more than 2 cm but less than 5 cm across.
• It has not spread to the lymph nodes or distant sites. 

Stage IIB

• The cancer is less than 5 cm across and has spread to nearby tissues such as muscles, tendons, and cartilage. 
• However, it has still not spread to the lymph nodes and distant organs. 

Stage IIIA

• Cancer may be of varying size and invade nearby tissues. 
• It has spread to the nearby lymph nodes (diagnosed through lymph node biopsy) but not to distant sites.

Stage IIIB

• Cancer may be of any size, spreading to the nearby tissues.
• Lymph node invasion is noticed on clinical examination, and imaging tests are confirmed by node biopsy. 
• The cancer has still not spread to distant sites. 

Stage IV

• In this stage, cancer is of any size, spreading to the nearby lymph nodes. 
• It also spreads to the distant lymph nodes and organs like lungs. 

What Causes Merkel Cell Carcinoma?

It is unknown how exactly Merkel cell carcinoma is caused in the body. It usually begins at the Merkel cells. Several research studies have recently discovered that a common virus, Merkel cell polyomavirus, which lives on the skin, plays a role in causing most Merkel cell carcinoma. 

However, other factors can increase your risk of developing Merkel cell carcinoma. These include:

• Excessive exposure to sunlight: Increased exposure to ultraviolet light from the sun and tanning beds increases your risk of Merkel cell carcinoma. 
• A weak immune system: Having infections like HIV can weaken your immune system, making you prone to develop Merkel cell carcinoma. 
• History of other skin cancers: If you have a history of previous skin cancers, such as basal cell or squamous cell carcinoma, you are more likely to develop Merkel cell carcinoma.
• Older age: The risk of Merkel cell carcinoma increases with age. It is more common in people over 50. 
• Light skin: White people are much more prone to develop this type of rare cancer than black people.
• Certain medications: Taking medications after organ transplant or immunosuppressants can also increase your risk of Merkel cell carcinoma.

What Are the Symptoms Associated with Merkel Cell Carcinoma?

Signs of Merkel cell carcinoma typically appear in sun-exposed areas of the body in the form of shiny or pearly lumps. These commonly appear on the face, eyelids, neck, and arms. However, they may also appear in other areas. 

The Merkel cell carcinoma lump may be:

• About the size of a dime and may spread quickly
• Dome shaped
• Raised 
• Firm and itchy 
• Resemble a pimple or an insect bite 
• Skin color, or red or bluish 
• Tender, painful, and sore 
• Having inflamed skin around it

How Do Doctors Diagnose Merkel Cell Carcinoma?

Your doctor may diagnose Merkel cell carcinoma through:

• A physical exam to assess the tumor lump
• Skin biopsy to study the tissue under a microscope
• Sentinel node biopsy to check the extent of the tumor 
• Imaging tests to check the tumor spread through CT (computed tomography) and PET (positron emission tomography) scans.

How is Merkel Cell Carcinoma Treated?

Treatment for Merkel cell carcinoma depends on the cancer stage. However, doctors mostly treat this type of skin cancer through surgical intervention. Surgical options include:

Mohs Surgery

• Here, the doctor will remove the tumor tissue and some part of the surrounding skin, leaving behind as much as healthy skin intact. 
• This is the most preferred treatment for Merkel cell carcinoma. 

Wide Local Excision

Here, the doctor will remove the tumor and some surrounding healthy skin.

Lymph Nodes Dissection 

• This procedure involves the removal of the tumor tissues along with the lymph nodes that have been affected. 

• You may require skin grafts or reconstructive surgery to repair and heal the treated area post-surgery. You may get cancer treatments to manage any remaining cancer cells. 

  These include:

  Chemotherapy 

  Immunotherapy

  Radiotherapy 

Can You Prevent Merkel Cell Carcinoma?

You can adopt the following tips to protect yourself from sun damage and lower your risk of developing Merkel cell carcinoma:

• Apply and reapply a broad-spectrum sunscreen every two hours when outdoors
• Avoid going outside between 10 am to 4 pm
• Avoid using tanning beds or sunlamps
• Dress in long-sleeved clothes 
• Learn self-exam techniques to monitor any signs of skin cancer  

Takeaway 

It is distressing to receive a skin cancer diagnosis like Merkel cell carcinoma. Though this cancer is rare and develops in older people, it can spread quickly and be life-threatening. Seek help from your doctor if you notice any changes like a fast-growing, skin-colored, or reddish lump on your face, eyelids, neck, or arms. Your doctor may surgically remove the tumor, depending on the stage. Additional therapies like chemotherapy, immunotherapy, and radiotherapy may follow this. 

Do not ignore your symptoms and seek help immediately to improve your quality of life.