Seborrheic keratoses start as small, rough bumps. They slowly thicken and often develop a warty surface. They range in color from white to tan, brown or gray. These common skin lesions can look threatening but are not cancerous and are easily treated.
Basal cell carcinomas often look like flat, firm, pale areas or small, raised, pink or red, translucent, shiny, pearly bumps that may bleed after a minor injury. They may have one or more abnormal blood vessels, a lower area in their center. Large basal cell carcinomas may have oozing or crusted areas.