Dermatofibromas are hard brown or red lumps under the skin. They usually develop on exposed areas of skin, such as the legs, arms, and back. Dermatofibromas do not develop into cancer. In general ...

When a cyst forms, the area becomes swollen. A cyst may be hard or soft. It may be large, but it can also be smaller than a pea. Some cysts can develop deep under the skin, while others occur near ...