[Paratrigeminal epidermoid originated in the meckel's cave (author's transl)]

We have reported a case of paratrigeminal epidermoid originated in the Meckel's cave. A 30 years old man was admitted to the department of neurosurgery with chief complaints of continuous right facial pain and numbness of entire right side of the face of three years duration. The positive neurological findings were hypesthesia over the distribution of the right trigeminal nerve, absence of the right corneal reflex and nystagmus on left lateral gaze. Caloric response was absent on the right side, however the audiogram showed normal. Cerebrospinal fluid examination was within normal limit. Electromyography showed giant spike in the right masseter and temporal muscles. Radiogram of the skull revealed a bone-destroying lesion over the medial florr of the right middle fossa involving the apex of the petrous bone (Fig 1). Right carotid angiography showed straightening and forward displacement of C4- C5 portion of the carotid siphon in the lateral view, and vertebral angiography showed displacement of basilar artery to the left side, upward displacement of the right posterior cerebral and superior cerebellar artery in the frontal view (Fig. 2, 3). At the time of operation, an epidermoid was identified in the Meckel's cave and totally removed microsurgically. Small amount of the tumor extending into the posterior fossa was also removed (Fig. 4, 5, 6, 7). Postoperative course was uneventfull except for an episode of headache and high fever of short duration, suggesting the signs of meningial irritation. Two months postoperativelly patient was relived of facial pain and was discharged with sensory impairment of the right trigeminal nerve distribution. Only 11 cases of paratrigeminal epidermoid, including the cases localized in the Meckel's cave have been reported in the past literatures (Table 1). In this paper we have discussed about the symptomatology and clinical data of paratrigeminal epidermoid and compared with those of trigeminal neurinoma, and meningioma originated in the same region. We would like to emphasize that the importance of differentiating the idiopathic trigeminal neuralgia from the paratrigeminal epidermoid, if the initial symptom of this tumor were tic douloureux. The total removal of epidermoid with capsule is essential treatment following the early diagnosis, however the attempt of total removal is sometimes difficult because of the relationship between the origin, size and extension of this kind of tumor to other important brain structures. And if some of the tumor is left behind at the time of operation, cholesterin meningitis is an important complication.