Merkel cell carcinoma

[Tracie Lynn]

Merkel cell carcinoma is a rare, rapidly spreading skin cancer that tends to affect older white people.
(See also Overview of Skin Cancer.)
Merkel cells are normal cells in the epidermis (the outer layer of the skin). These cells mostly function as touch receptors and they produce certain hormones. Merkel cell carcinoma arises from uncontrolled growth of cells in the skin that share some characteristics with normal Merkel cells.
Merkel cell carcinoma is diagnosed at an average age of 75. Merkel call carcinoma also affects younger people whose immune system is weakened. Sun exposure increases the risk, as does having another cancer. The Merkel cell polyomavirus may be a contributory factor. This cancer commonly spreads to the lymph nodes.