Picture of Epidermal Inclusion Cyst (EIC)
Epidermal inclusion cysts are the most common cutaneous cysts of the skin. They are also known as sebaceous cyst, epidermoid cyst, epidermal cyst, infundibular cyst, inclusion cyst, and keratin cyst. These cysts can occur anywhere on the body, typically present as nodules directly underneath the patient's skin, and often have a visible central punctum. The contents are cheese-like and are usually freely moveable. The size of these cysts can range from a few millimeters to several centimeters in diameter. Lesions may remain stable or progressively enlarge over time. A rupture is usually associated with pain and inflammation.
Text Source: National Library of Medicine/National Center of Biotechnology Information