INTRACRANIAL EPIDERMOIDS OCCURRING SIMULTANEOUSLY BELOW AND ABOVE THE TENTORIUM

Abstract

The term epidermoid (cholesteatoma) refers to a slow growing, cystic neoplasm which may occur in or beneath the scalp, within or about the orbit, in the neck, jaws, middle ear, mastoid, cranial bones or elsewhere along the craniospinal axis. The manner of origin is said to be by inclusion of epiblastic tissue during the closure of clefts or at a point of contact of ectodermal invagination with other tissues in the development of the embryo.¹Another presumptive source is epidermal implantation resulting from trauma, an example of which has been recorded by Graumann.²Up to the time of writing 205 cases of intracranial epidermoid tumor have been recorded in the literature. Of this number there were 7 in which the lesion was situated in both the supra-tentorial and the infratentorial position. The purpose of this paper is to review these 7 cases and to add the eighth. The