Basel cell carcinomas, which typically manifest as raised or flat red patches that contain abnormal blood vessels, can occur anywhere on the body, including the legs, the American Cancer Society explains. Melanomas often look like moles, but they typically have jagged or asymmetrical edges.
The lower legs are one of the primary spots where women develop melanoma, the most dangerous form of skin cancer, according to WebMD. Because melanomas can grow quickly, anyone with a suspicious mole should see a dermatologist. The American Cancer Society and WebMD both host online slideshows of skin cancer photos, including photos of skin cancer on the legs.