Massachusetts General Hospital

Sebaceous Cysts

What are sebaceous cysts?

Sebaceous cysts are more accurately called epidermal cysts, although both terms have been used interchangably. These cysts are typically harmless, slow-growing bumps under the skin, often appearing on the scalp, face, ears, trunk, back, or groin area. They can arise from a ruptured follicle associated with acne, or be seen in a developmental defect of a sebaceous duct, or from trauma to the area. Sometimes they develop without clear explanation. The cysts usually contain keratin, lipid, and other skin particles. Cysts can remain stable or progessively grow. Sometimes they will become inflamed or spontaneously rupture, which poses a risk for infection 

Treatment for sebaceous cysts

Sebaceous cysts may resolve on their own, but tend to recur. Treatment is not required unless it is the patient's preference. These cysts can be injected with medicine to reduce inflammation and prevent the need to drain them. Infected cysts, however, may require incision and drainage by puncturing the top and removing its contents.

Large cysts can reappear after this procedure and may have to be surgically removed. If a cyst becomes swollen, tender, large, or infected, treatment may include antibiotics and then surgical removal.