Merkel Cell Carcinoma

Merkel cell carcinoma typically appears as a painless, firm, red, or purplish nodule on the skin. These nodules often grow rapidly and may be mistaken for other types of skin conditions, such as cysts or benign tumors. Merkel cell carcinoma most commonly occurs on sun-exposed areas of the skin, such as the head, neck, and extremities, but it can also develop on areas not typically exposed to sunlight.

The exact cause of Merkel cell carcinoma is not fully understood, but several factors are believed to contribute to its development:

• Merkel Cell Polyomavirus (MCPyV) Infection: In about 80% of cases, Merkel cell carcinoma is associated with infection by Merkel cell polyomavirus (MCPyV). This virus integrates into the DNA of cells, leading to genetic mutations and the development of cancer. However, most individuals infected with MCPyV will not develop Merkel cell carcinoma, suggesting that other factors play a role in its development.
• UV Radiation Exposure: Prolonged exposure to ultraviolet (UV) radiation from sunlight or artificial sources, such as tanning beds, is a significant risk factor for Merkel cell carcinoma. This is supported by the fact that Merkel cell carcinoma often occurs on sun-exposed areas of the skin, such as the head, neck, and arms.
• Immunosuppression: Individuals with a weakened immune system, such as organ transplant recipients or those with HIV/AIDS, have an increased risk of developing Merkel cell carcinoma. A compromised immune system may allow for the proliferation of MCPyV-infected cells or impair the body’s ability to control abnormal cell growth.
• Older Age: Merkel cell carcinoma most commonly affects older adults, with the average age of diagnosis being in the late 60s to early 70s. The risk of developing Merkel cell carcinoma increases with age.
• Fair Skin: Like most other skin cancers, individuals with fair skin, light-colored eyes, and a history of sunburns are at higher risk of developing Merkel cell carcinoma.

The diagnosis of Merkel cell carcinoma is typically made through a combination of medical history, physical examination, and often a skin biopsy. Unlike other types of cancer, you can see skin cancers. This makes it easier to detect them early. Skin cancer screening exams and self-exams at home help detect skin cancer earlier. If you notice a new or suspicious spot on your skin it is best to check in with a board-certified dermatologist and skin cancer expert like Dr. Thomas Knackstedt.

Here’s how the process generally unfolds (ideally the following paragraphs are separated by arrows):

Medical History

The team at Apex Skin Center will inquire about your medical history, including any previous skin conditions, sun exposure habits, family history of skin cancer, and any symptoms or changes in the skin.

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Physical Examination

Board-certified dermatologist Dr. Knackstedt will conduct a thorough examination of the skin, focusing on any suspicious lesions or growths. Dermoscopy, a tool that allows for the magnification of structures within a skin growth is used to aid in the diagnosis of Merkel cell carcinoma and can help differentiate Merkel cell carcinoma from benign growths.

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Skin Biopsy

If Dr. Knackstedt suspects Merkel cell carcinoma based on the physical examination and dermoscopy findings, a skin biopsy may be performed. During a skin biopsy, a small sample of tissue is removed from the suspicious lesion under local anesthesia (numbing) and sent to a laboratory for analysis. The tissue is examined under a microscope to confirm the presence of Merkel cell carcinoma and to assess the cancer’s characteristics.

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Once the diagnosis of Merkel cell carcinoma is confirmed, further evaluation may be necessary to determine the extent of the cancer and plan appropriate treatment. As a fellowship trained, board-certified Mohs surgeon and dermatology oncologist (cancer specialist), Dr. Thomas Knackstedt and the team at Apex Skin Center have significant expertise in the management of all types of skin cancer.