Epidermoid cysts(sebaceous cysts)
DEFINITION
Epidermoid (ep-ih-DUR-moid) cysts are noncancerous small bumps beneath the skin. Epidermoid cysts can appear anywhere on the skin, but are most common on the face, neck and trunk.
Slow growing and often painless, epidermoid cysts rarely cause problems or need treatment. But you may 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).
CAUSES
The surface of your skin (epidermis) is made up of a thin, protective layer of cells that your body continuously sheds. Most epidermoid cysts form when these cells move deeper into your skin and multiply rather than slough off.
The epidermal cells form the walls of the cyst and then secrete the protein keratin into the interior. The keratin is the thick, yellow substance that sometimes drains from the cyst. This abnormal growth of cells may be due to a damaged hair follicle or oil gland in your skin.
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).
SYMPTOMS
Epidermoid cyst signs and symptoms include:
- A small, round bump under the skin, usually on the face, trunk or neck
- A tiny blackhead plugging the central opening of the cyst
- A thick, yellow, foul-smelling material that sometimes drains from the cyst
- Redness, swelling and tenderness in the area, if inflamed or infected
When to see a doctor
Most epidermoid cysts don’t cause problems or need treatment. See your doctor if you have one that:
- Grows rapidly
- Ruptures or becomes painful or infected
- Occurs in a spot that’s constantly irritated
- Bothers you for cosmetic reasons
