This is not only the most common type of skin cancer, but the most common type of cancer in humans. About 8 out of 10 skin cancers are basal cell carcinomas (also called basal cell cancers). They usually develop on sun-exposed areas, especially the head and neck. Basal cell carcinoma was once found almost entirely in middle-aged or older people. Now it is also being seen in younger people, probably because they are spending more time out in the sun. When seen under a microscope, basal cell carcinomas share features with the cells in the lowest layer of the.