Merkel-cell carcinoma

Merkel-cell carcinoma (MCC) is a rare and aggressive skin cancer happening in about 3 per 1,000,000 population. It is also known as cutaneous APUDoma, primary neuroendocrine carcinoma of the skin, primary small cell carcinoma of the skin, and trabecular carcinoma of the skin. 
Reasons why the cancer would form is because of Merkel cell polyomavirus (MCPyV or MCV), a weakened immune system, and exposure to ultraviolet radiation. 
Merkel-cell carcinoma usually shows up on the head, neck, perianal and eyelid. It is more common in elderly people.