Türk Nöroşirürji Dergisi 2017 , Vol 27 , Num 1
Surgical Approaches to the Posterior Fossa Epidermoid Tumors
Ahmet Hilmi KAYA1,Adnan DAĞÇINAR3,
1Anadolu Sağlık Merkezi Hastanesi, Beyin ve Sinir Cerrahisi Bölümü, İstanbul Türkiye
2Gelişim Üniversitesi, Sağlık Bilimleri Yüksek Okulu, İstanbul, Türkiye
3Marmara Üniversitesi, Tıp Fakültesi, Beyin ve Sinir Cerrahisi Anabilim Dalı, İstanbul, Türkiye
Epidermoid tumors are benign and slowly growing congenital lesions which are thought to originate from ectopic remnants of epidermal elements during neural tube formation between the third and fifth weeks of embryonic life. They represent 0.3% to 1.8% of all primary intracranial tumors. Epidermoid tumors are usually located in cerebellopontine angle, parasellar region, middle cranial fossa, diploid space in skull, spinal canal and rarely intracerebral. To distinguish epidermoid tumors from other intracranial lesions, appropriate neuroimaging tools should be utilized. Diffusion-weighted magnetic resonance imaging is definitive for the diagnosis. Mollaret"s meningitis, a recurrent aseptic inflammation, is known to be associated with epidermoid tumors. Although total resection of these tumors is the definitive treatment to prevent recurrence, it is not always possible to complete resection of the capsule which is firmly adherent to neural and vascular elements within the subarachnoid space. According to Yasargil, radical resection is possible via retrosigmoid suboccipital approach in most cases; even when they spread out of posterior fossa. Because of their tendency to grow up through basal cisterns, epidermoid tumors provide a relatively convenient space for resection by widening the surgical corridor. Combination with supraserebellar infratentorial approach would give opportunity to reach mesencephalic, pineal, parasellar and temporobasal regions. In some cases, using endoscopic assistance with microscope could be useful for better exposition of the tumor. Anahtar Kelimeler : Posterior fossa, Epidermoid tumor, Surgery