Sebaceous cyst
Specialty	Skin

A sebaceous cyst (a form of trichilemmal cyst; also called: keratin cyst; sometimes wrongfully called: epidermal cyst or epidermoid cyst (see ICD-10 L72.0)) is a closed sac or cyst below the surface of the skin that fills with a fatty white, semi-solid material called sebum.

The scalp, ears, genitals, and face are common sites for sebaceous cysts, though they may occur anywhere on the body except the palms of the hands and soles of the feet. They are smooth to the touch, vary in size, and are generally round in shape.

They are generally mobile masses that can consist of fibrous tissues and fluids, to a fatty, (sebaceous), substance that resembles cottage cheese, or a somewhat viscous, serosanguinous fluid, (containing purulent and bloody material). A cyst can be excised in its entirety or, more commonly, can rupture during excision and removal. Cysts can recur, either if they are ruptured or not.

Causes

Blocked sebaceous glands, swollen hair follicles, and traumatic implantation of surface epithelium beneath the skin can cause such cysts.[1]

Treatment

Sebaceous cysts are not cancerous and do not generally require medical treatment. However, if they continue to grow, they may become unsightly, painful, infected, or all of the above. Surgical excision of a sebaceous cyst is a simple procedure to completely remove the sac and its contents. An infected cyst may require oral antibiotics or other treatment before excision.

External links

• Minimal Excision Technique for Epidermoid (Sebaceous) Cysts
• NIH/Medline
• University of Maryland
• eMedicine (article "Epidermal Inclusion Cyst")
• Case study abstract epidermoid cyst of the foot