Merkel cell carcinoma (MCC) is a rare but aggressive type of skin cancer that originates in Merkel cells, which are found in the top layer of the skin (epidermis). These cells are neuroendocrine in nature, involved in the sensation of touch by being close to nerve endings
Key Characteristics of Merkel Cell Carcinoma:
- Aggressiveness: MCC tends to grow quickly and has a high risk of spreading (metastasizing) early to lymph nodes and other organs such as the liver, lungs, brain, and bones
- Appearance: It usually presents as a painless, firm, shiny nodule or bump on the skin, often flesh-colored, red, or blue. It most commonly appears on sun-exposed areas like the face, head, neck, and extremities
- Risk Factors: Major risk factors include long-term exposure to ultraviolet (UV) light, a weakened immune system, older age (typically over 50 or 60 years), fair skin, and infection with Merkel cell polyomavirus (MCPyV)
- Incidence: It is very rare, occurring in about 3 people per million annually in the U.S., and is about 40 times less common than melanoma. Approximately 3,000 new cases are diagnosed yearly in the U.S.
Clinical Course and Prognosis:
- MCC often recurs after treatment and spreads rapidly, making it potentially life-threatening
- It is the second most common cause of skin cancer death after melanoma
- Diagnosis is confirmed by biopsy, and treatment depends on the stage of the disease
Summary:
Merkel cell carcinoma is a rare, fast-growing skin cancer arising from neuroendocrine Merkel cells in the epidermis. It is linked to UV exposure, immune suppression, and viral infection, and it primarily affects older adults with fair skin. Due to its aggressive nature and tendency to metastasize early, prompt diagnosis and treatment are critical
