Endoscopic Surgery for Third Ventricular Colloid Cysts in the Absence of Hydrocephalus- a feasibility study

Purpose: The aim of this study was to investigate the feasibility and effectiveness of endoscopic neurosurgery for patients with third ventricular colloid cysts without ventriculomegaly.Methods: Seventy-one patients with third ventricular colloid cysts were identified and recruited to this study. Eighteen of these patients did not have concomitant hydrocephalus and underwent primary endoscopic surgery for cyst resection. The surgical technique, the success rate, and patients’ outcome were assessed and compared with 53 hydrocephalic patients who underwent similar procedures.Results: The ventricular compartments were successfully cannulated and gross total resectin of the colloid cysts was achieved in all patients. There were no operative complications related to the endoscopic procedure. Two patients required subsequent intervention for hydrocephalus. The success rate for endoscopic surgery in non-hydrocephalic patients was similar to its value in patients with hydrocephalus.Conclusion: Endoscopic resection of third ventricular colloid cyst in patients without hydrocephalus seems to be feasible, effective and not contraindicated

Isolated trochlear nerve schwannoma presenting with diplopia: A case report and literature review

Background: Trochlear nerve schwannoma is a very rare tumor encountered especially in patients without type 2 neurofibromatosis (NF2). Most of the time, this tumor is diagnosed intraoperatively. We describe a rare case of trochlear nerve schwannoma. Clinical Presentation: A 63-year-old male presented with generalized headache from 8 months earlier, without nausea and vomiting. The headache had worsened during the last months. Clinically, he suffered from transient diplopia. Magnetic resonance imaging (MRI) demonstrated a mass in the left ambient and interpeduncular cisterns that was compressing the midbrain and upper pons. The preoperative impression was of trigeminal schwannoma. However, intraoperatively, the tumor originated in the trochlear nerve. The mass was removed entirely via left suboccipital retrosigmoid approach. The histopathology diagnosis confirmed schwannoma. The patient's diplopia did not improve postoperatively. Conclusion: Trochlear nerve schwannoma is a rare type of schwannoma and in almost all of the cases is diagnosed intraoperatively. There are three types of trochlear nerve schwannoma according to the classification proposed for trigeminal schwannoma: cisternal type—confined to the precavernous segment of the trochlear nerve; cistocavernous type—invading the cavernous sinus and the retroclival and retropetrosal cistern; cavernous type—located in the middle cranial fossa on the cavernous or paracavernous segment of the fourth cranial nerves, with or without cavernous sinus invasion. The cisternal type was the most common type encountered in previous studies. The clinical signs and symptoms of trochlear nerve schwannoma are similar to the trigeminal schwannoma and should be considered in the differential diagnosis of trigeminal schwannoma