Intradiploic Epidermoid of the Skull

Definition An epidermoid cyst may be defined as a cyst arising from ectodermal cell-rests, and in particular from epidermal primordia. In the literate, varieties of cysts from dermoids, both sequestration and implantation types to cholesteatomas, have been included under the heading of epidermoids. Some authors have included wens or sebaceous cysts in the classification of epidermoids. In a simple dermoid, epidermis, derma and dermal glands appear in j^e form of a cyst. In the true epidermoid, however, definite dermal structures are wanting. Epidermoids may be traumatic in origin, but congenital epidermoids may also result due to displacements of the epithelium.