Basal cells are found at the bottom of the top layer of skin (epidermis). These cells produce new skin cells.
Normally, cells in the body will grow and divide to replace old or damaged cells. This growth is usually precise. Once enough cells are produced to replace the old ones, normal cells stop dividing. Tumors occur when there is an error and cells continue to grow uncontrollably. Basal cell carcinoma develops from basal cells.
Basal cell carcinoma most often appears on areas of the body that have been exposed to the sun, such as the head, face, neck, back, chest, or shoulders. Basal cell carcinoma grows slowly and does not usually spread to other parts of the body (metastasize).
Basal cell skin carcinoma is the most common skin cancer in light-skinned people. It is rare in people who have dark skin.