Epidermoid Cysts of the Head

Types and categories of epidermoid and dermoid cysts. 1: Cyst strictly underneath the skin. 2: Cyst underneath the skin and within the skull. 3a and 3b: Cyst or fistula mainly within the skull. Both variants extend to the dura. 4: Distinct impression of the dura by the cyst which perforates the bone like a sandglass. 5 a to d: Varieties of cysts which perforate the dura either without or with a fistula with an ostium at the surface of the skin. The knowledge of these categories is important due to the inherent danger of complications, and for a total excision.