Three Subtypes of Trigeminal Schwannoma in Relation with Meninges Pattern for Surgical Consideration: Anatomy and Histological Study

Background: Trigeminal schwannomas may originate from the root, the ganglion, or the peripheral branches of the trigeminal nerve. Trigeminal schwannomas are rare tumors that comprise of 0.2% of all intracranial tumors. Objective: To clarify the pattern of trigeminal schwannomas in relation with meninges for surgical considerations. Methods: We used 3 adults head cadaver specimens were used for surgical simulation and taken for immunohistochemical staining to observe the meninges pattern and applied in surgical technique. Results: This was confirmed qualitatively with Masson’s Trichrome staining for collagen and elastin for the cranial dura. In our study we found that the dura wrapped the trigeminal nerve from the beginning of gaserian gangglion which change into interdural space. It becomes periosteal dura after passing through the foramen, we call it extracranial part. The Myelin basic protein staining shows the nerve filament which covered by piamater at the root entry zone.The arachnoid clearly covers the nerve bundle from entering Meckel cave and becoming perineurium in the interdural space. At the extracranial part the nerve filamen or bundle is only covered by periosteal dura or similar to epineurium structures. Conclusion: From our discussion get conclusion for surgical method, that is 1. We did surgery sub arachnoidal dissection in posterior fossa, 2. submeningoperisoteal dura dissection in middle fossa 3. subperiosteal dissection in infra temporal fossa.