[Non-acoustic parastemal schwannomas: results of treatment]

The paper presents the results of treatment in 15 cases with non-acoustic parastemal schwannomas, which amounts to 4.3% in this histological subgroup. Among them, there were 7 (2.0%) patients with trigeminal tumors, 5 (1.4%) with facial nerve schwannomas, 3 (0.9%) with schwannomas, which were localized in the jugular foramen. In 4 (57.1%) cases, trigeminal schwannomas were localized in the posterior fossa and in (3.42.9) cases, they spread into the infra- and supratentorial areas. Tumors of the jugular foramen spread extracranially in 2 (66.7%). Their diagnosis was based on clinical intrascopic (computed tomographic and magnetic resonance imaging) data. All the cases had sings of acousticofacial disorders. For tumor removal, the suboccipital retrosygmoid approach was used in 12 cases and combined approaches were applied in 3 cases, including 2 (13.3%) patients in whom schwannomas were removed via two- or three-stage interventions. The anatomic integrity of the cranial nerves adjacent to a tumor was preserved in all the cases. After surgery, their mild or moderate dysfunction that did not lower life quality was observed in most cases. Liquorea and meningitis were seen in 1 (6.7%) case after removal of an extracranial component of trigeminal schwannoma. Radical tumor resection was made in 93.3% of cases. Tumor recurrence was observed in 1 (6.7%) case. There were no fatal cases in a group of the patients operated on. Larger tumors that induce severe deformation of the brain stem should be removed in two steps; this makes it possible to rule out their rapid redislocation that deteriorates the course of an early postoperative period.