[A case report of epidermoid carcinoma in the cerebello-pontine angle]

A case of epidermoid carcinoma in the cerebello-pontine (CP) angle is presented. A 42-year-old male was admitted with a complaint of experiencing double vision for four months in January, 1992. During neurological examination, right abducens palsy, right facial dysesthesia, and atrophy of the right temporal muscle were noted. Magnetic resonance (MR) imaging revealed a mass of low intensity in the right CP angle, which was prominently enhanced with gadolinium. Malignancy was suspected because the tumor on MR enlarged rapidly in a month, so the first surgical resection was performed. Suboccipital exploration of the right CP angle was performed in February. At first, a fragile, pearly part of the mass typical of epidermoid was exposed behind the seventh and eighth cranial nerve complex. Then, a grayish, fibrous part was exposed, which involved the fifth cranial nerve and was attached to the tentorium and the brainstem. Histological diagnosis of the fragile part of the tumor revealed a typical epidermoid cyst and that of the fibrous part was squamous cell carcinoma. During postoperative examinations on other parts of the body, such as endoscopic studies of the trachea and the esophagus, no abnormality was shown. Therefore the tumor was diagnosed as a primary intracranial epidermoid carcinoma. Post-operatively, conventional fractionated external-beam focal irradiation was carried out, which caused regression of the residual tumor for eleven months. Subsequently, palsy of the right side of the tongue and paresis of the contralateral side of the extremities and face developed with increase of the right abducens palsy. MR imaging indicated regrowth of the tumor. The second operation via the subtemporal approach was unsuccessful, because the tumor was fibrous and firmly attached to the brainstem.(ABSTRACT TRUNCATED AT 250 WORDS)