Epidermoid (ep-ih-DUR-moid) cysts are noncancerous small bumps beneath the skin. They can appear anywhere on the skin, but are most common on the face, neck and trunk.
Epidermoid cysts are slow growing and often painless, so they rarely cause problems or need treatment. You might choose to have a cyst removed by a doctor if its appearance bothers you or if it's painful, ruptured or infected.
Many people refer to epidermoid cysts as sebaceous cysts, but they're different. True sebaceous cysts are less common. They arise from the glands that secrete oily matter that lubricates hair and skin (sebaceous glands).