Epidermoid cysts are caused either by cells that move ... when branchial arches—which are responsible for developing certain parts of your head and neck—don’t fuse, or grow together.

also known as epidermal inclusion cysts, are benign keratin-filled bumps, that develop under the skin and are commonly present on the face, neck, scalp, and trunk. Pilar cysts are common benign ...

Some cysts can develop deep under the skin, while others occur near the surface, where they can create a white or yellow head. Usually, cysts do not hurt unless they are large or an infection ...