What is an Epidermoid Cyst?

An epidermoid cyst is a closed sac which develops under the skin. It usually grows slowly and starts out very small. These cysts are typically benign in nature although sometimes they can rupture or cause an abscess, and in rare cases they may be linked with cancers of the skin. Evaluation and treatment of epidermoid cysts is provided by a dermatologist in most cases, although sometimes a general practitioner can address the issue.

These cysts form when epithelial cells end up trapped under the skin instead of naturally shedding. These cells start to multiply, creating a sac which is lined with skin cells. The sac fills with keratin and sebum and eventually starts to swell. Visually, epidermoid cysts are usually white or yellow and they are movable under the skin. People with dark skin may develop darker epidermoid cysts.

Alternate terms which may be used to refer to an epidermoid cyst include keratin cyst, infundibular cyst, sebaceous cyst, and epithelial cyst. These cysts most commonly appear on the back, face, scrotum, and neck. They can sometimes be irritating or painful, especially if they are located at a site where they are subjected to pressure from clothing or glasses. Epidermoid cysts may be a cosmetic concern in some cases, as they are unsightly.

When people notice what appears to be an epidermoid cyst, it can be a good idea to see a dermatologist to confirm the diagnosis. If the cyst is not painful and it is not causing a cosmetic problem, the doctor may recommend leaving it as is. If it is painful or looks like it might become infected, the doctor will recommend removing it. Epidermoid cyst removal is an outpatient procedure which can be done in the office, and at the same time the doctor can take a sample for biopsy if there are concerns about malignancy. Once the cyst is removed, the doctor may recommend taking prophylactic antibiotics for protection until the site heals.

A patient who is not yet ready to pursue removal might want to consider epidermoid cyst treatment to see if this resolves the issue. Applying warm compresses to cysts can help them resolve and address pain and irritation. There are also topical medications, such as steroids, available to treat inflammation at the site of the cyst. Results take longer with nonsurgical treatment, but this option can be less invasive and less expensive. It is also less likely to lead to scarring.