What is Merkel cell carcinoma?
Merkel cell carcinoma (MCC) is a rare, aggressive type of skin cancer that forms on or just under the skin. It is also called primary small cell carcinoma of the skin, trabecular carcinoma, APUDoma, neuroendocrine carcinoma, endocrine carcinoma, or primary undifferentiated tumor of the skin (1). MCC is believed to start in neuroendocrine cells called Merkel cells. These cells release hormones into the blood when stimulated by the nervous system. They migrate from part of the nervous system called the neural crest to the skin (2). Merkel cells are believed to play a role in making the skin sensitive to touch (3). • How often does Merkel cell carcinoma occur? Approximately 1,200 new cases of MCC are diagnosed in the United States each year (4), compared with almost 60,000 new cases of melanoma and more than 1 million new cases of nonmelanoma skin cancer. The incidence of MCC has been rising, with a 3-fold increase between 1986 and 2001 (4). Most patients diagnosed with MCC are over age 5
