Merkel cell carcinoma (MCC) of the skin is a rare, aggressive skin cancer the affects lighter skinned adults. MCC has a high rate of local recurrence and lymph node spread.

What is Merkel cell carcinoma?

Merkel cell carcinoma (MCC) is a rare skin cancer that tends to be very aggressive. While originally thought to arise from Merkel cells (cells located in the base of the top skin layer), it’s cell of origin is controversial. MCC tends to arise on sun-exposed areas of the skin.

What causes MCC?

Several risk factors have been associated with the development of MCC. These include:

• Merkel cell polyomavirus – a virus thought to be part of the human skin microbiome. In one study of patients with MCC, skin samples from tumors showed Merkel cell polyomavirus positivity in 71% of patients.
• Ultraviolet (UV) radiation – UV radiation, especially to the sun, is thought to play an important role in the etiology of many cases of MCC.
• Immunosuppression – The incidence of MCC is increased in immunosuppressed patients, including organ transplant recipients, HIV-infected individuals, and those with certain blood malignancies.

How is MCC diagnosed?

Your board-certified dermatologist will conduct an examination of the skin. Diagnosis of MCC is made by a skin biopsy, which is a small tissue sample that is sent to a lab for microscopic analysis. Because of its rarity, MCC is often clinically misdiagnosed as a benign lesion, such as a cyst or a lipoma. A high index of suspicion is required for the diagnoses to be made without delay.

What are the warning signs of MCC?

MCC typically arises in older patients with light skin tones as a rapidly growing, painless, firm, nontender, shiny, skin-colored or bluish-red bump. Lesion features of MCC can be remembered by using the acronym AEIOU:

• Asymptomatic – 88% of tumors
• Expanding rapidly (significant growth in < 3 months) – 63%
• Immune suppression (HIV infection, solid organ transplant recipient, chronic lymphocytic leukemia) – 8%
• Older than 50 years of age – 90%
• Ultraviolet (UV)-exposed area in a fair-skinned individual – 81%
• The presence of at least three of these features increases the suspicion of MCC and a biopsy should be considered.

What are the treatment options?

The choice of treatment depends on the location, size, depth of the tumor, whether the tumor has spread to other parts of the body and your age and health. Treatment may include surgery to remove the tumor with the addition of radiation therapy. Additionally, radiation therapy may be used alone without surgery in persons whom surgical removal is not feasible or are medically unfit for surgery.

Your board-certified dermatologist may recommend a sentinel lymph node (SLN) biopsy. A sentinel lymph node biopsy is an operation where a surgeon finds, takes out, and checks the first lymph node where a tumor may have spread to. This procedure is usually performed under general anesthesia. This means you will get medicines through a small tube into a vein or gases that you breathe through a mask to make you unconscious.

In some cases, chemotherapy or immunotherapy may be recommended. Chemotherapy is a type of cancer treatment that uses one or more anti-cancer drugs are part of a regimen to either cure, prolong life, or reduce symptoms. Immunotherapy is the treatment of a disease by activating your own immune system to fight off cancers.

Everyone should have an annual skin check for skin cancer. When you are concerned about a skin lesion, contact Phoenix Surgical Dermatology Group. to schedule a consultation. Don’t wait. Early diagnosis and treatment are the keys to a successful outcome.