Many patients are concerned when they develop a bump that looks like a cyst.

This is usually a sebaceous cyst that is a closed sac found under the skin, usually on the trunk, neck, or face. They are filled with a oily or cheese-like matter and usually are painless.

In some cases, however, cysts can get inflamed and become tender to the touch. They are also called epidermal cysts, wens, keratin cysts, or epidermoid cysts. Most often, sebaceous cysts come out of hair follicles or can form as a result of trauma to the skin. Usually they are benign, but they must be differentiated from other potentially malignant bumps that can mimic cysts.

In some cases, the dermatologist will perform a biopsy to rule out certain conditions. If a small cyst becomes inflamed, a dermatologist can inject it with an anti-inflammatory medication to reduce swelling or just remove it entirely with surgery.