What type of skin cancer arises from keratinocytes?

Squamous cell carcinoma arises from keratinocytes, which are the predominant cell type in the outer layer of the skin (epidermis). These cells are responsible for producing keratin, a key protein that helps form the skin's protective barrier. Squamous cell carcinoma typically develops in areas of the skin that have been exposed to UV radiation, such as the face, ears, and hands.

This type of cancer is characterized by the abnormal growth of squamous cells, which can lead to the formation of scaly patches, open sores, or elevated growths with a central depression. While it can sometimes spread to other parts of the body, squamous cell carcinoma is often more manageable and has a better prognosis compared to melanoma, which is another type of skin cancer that originates from melanocytes, the pigment-producing cells of the skin.

Basal cell carcinoma, on the other hand, arises from basal cells in the lower part of the epidermis and is the most common form of skin cancer, but it is separate from keratinocyte-derived squamous cell carcinoma. Merkel cell carcinoma originates from neuroendocrine cells found in the skin, rather than keratinocytes.