[Intracranial high density epidermoid--classification of CT scan findings and chemical analysis of the cystic content (author's transl)].

The author described an epidermoid which revealed homogenous high density in CT scan without contrast enhancement. Sixteen reported cases of intracranial epidermoid with CT scan including our 4 cases were classified in three types; Type I; classical pearly tumor of low density with no contrast enhancement. Type II; low density mass with marginal high density ring by contrast enhancement. Type III; homogenous high density mass with no contrast enhancement. The reason of high density in CT scan was considered mainly due to the peculiar cystic content, which was brown in color and gelatinous. Chemical analysis of the cystic content disclosed various heavy metals and high protein content, however, it was indicated that the high protein concentration was solely attributable to the high density EMI number.