Epidermoid Tumor of Posterior Fossa : Analysis of 10 Cases

후두개와 유표피낭종 : 10례 분석

Objectives : The purpose of this study was to evaluate the clinical features of the epidermoid tumor of posterior fossa and to assess the surgical outcome. Methods : We reviewed the clinicoradiological records of 10 epidermoid tumor of posterior fossa, treated surgically at our hospital between 1991 and 1996. Results : The mean age of onset was 36 years old and mean duration of symptom was 5.2 years. Six were men and four were women. The location of tumors were cerebellopontine angle(CPA) 5 cases, cerebellum(Cbll)& 4th ventricle 3 cases, foramen magnum 1 case, and pineal region extended to Cbll and 4th ventricle 1 case. Common clinical features were trigeminal neuralgia in 3 cases, cerebellar signs 2 case, headache 2 cases, hemifacial spasm with deafness 1 case, cbll signs and multiple cranial nerve dysfunctions 1 case. One CPA epidermoid had no clinical symptom and sign associated with the tumor. The surgical approaches were suboccipital approach in 9 cases and one transcallosal approach to the tumor of pineal region. The extent of surgical removal was gross total resection in 5 cases and near total or subtotal resection in 5. Two patients with CPA tumor were complicated with facial paresis. One patient with tumor located in cerebellum extended into cisterna magna had postoperative vocal cord paresis. All complicated cases had severe adhesion of tumor capsule with brainstem or cranial nerve. The mean duration of follow up was 26 months. The overall outcome was improvement of symptoms and signs in 6 cases and stationary 4 cases. During follow up, imaging study was done in 7 patients and none of them had finding of tumor recurrence. Conclusion : We conclude that recurrence of tumor is rare in both total and subtotal resected cases, but long-term follow-up is required. Aggressive removal of tumor capsule that adhesed to brianstem or cranial nerve is avoided for preventing severe postoperative complication.