Sebaceous cysts are common noncancerous cysts of the skin. Cysts are abnormalities in the body that may contain liquid or semiliquid material.
Sebaceous cysts are mostly found on the face, neck, or torso. They grow slowly and are not life-threatening, but they may become uncomfortable if they go unchecked.
Sebaceous cysts form out of your sebaceous gland. The sebaceous gland produces the oil called sebum that coats your hair and skin. Cysts can develop if the gland or its duct, the passage where oil is able to leave, becomes damaged or blocked. This usually occurs due to a trauma to the area.
The trauma may be a scratch, a surgical wound, or a skin condition, such as acne. Sebaceous cysts grow slowly, so the trauma may have occurred months or weeks before you notice the cyst.
Other causes of a sebaceous cyst may include:
- a misshapen or deformed duct
- damage to the cells during a surgery
- genetic conditions, such as Gardner’s syndrome or basal cell nevus syndrome