[Cerebello-pontine angle epidermoid with cerebellar atrophy; report of a case]

The inside of an epidermoid is formed by masses of epithelial debris, desquamative keratin and cells derived from the epithelial capsule which accumulate very slowly within the capsule. As a result, the growth of the tumor is very slow, and the clinical signs are very diverse and bizarre because of the situation and extension of the epidermoids throughout the basal cisterns. A 52-year-old housewife was admitted to our clinic with complaints of dizziness and gait disturbance. The abnormal neurological findings were truncal ataxia, lt-trigeminal disturbance, lt-facial palsy, lt-hearing disturbance, lt-cerebellar signs (dysmetria, dysdiadochokinesia) and nystagmus. CT scan revealed low density area in the prepontine cistern and lt-cerebello-pontine angle, which was not enhanced following intravenous injection of the contrast medium. Metrizamide CT cisternography showed staining of the tumor heterogeneously revealing a honeycomb appearance. MRI showed the tumor clearly as well as the severe atrophy of the lt-cerebellar hemisphere and the pontine basal area. In this case atrophy of the cerebellar hemisphere and pons may have resulted from being compressed by the tumor. Because of this, we think it necessary to stress that early diagnosis and operation of the epidermoid are very important.