Schwannoma originating in lateral recess of the fourth ventricle
This 30-year-old male patient presented to us with headache and episodes of giddiness on and off for past 4 to 5 months. He did not have any history of difficulty in walking or loss of unconscious. He did not have any evidence of Von Recklighauson's neurofibromatosis. Neurological examination was unremarkable except minimal left-sided cerebellar signs. His routine biochemical and hematological parameters were normal. Computed tomography scan revealed a posterior fossa mass in the region of left half of fourth ventricle and adjacent to middle cerebellar peduncle with perilesional edema, which was enhancing on contrast administration. Magnetic resonance imaging showed a solid mass occupying the left half of the fourth ventricle, which was isointense on T1 WI and hyperintense on T2 WI and brightly enhancing on gadolinium administration [Figures and ]. The mass was causing edema and pressure effect on middle cerebellar peduncle. Patient was operated via midline suboccipital craniectomy with removal of posterior arch of C1 and complete excision of tumor has been done. Tumor was visualized on lifting left cerebellar tonsil. It was well-encapsulated, grayish white, firm in consistency but easily breakable and vascular. Branches from posterior inferior cerebellar artery supplied the tumor, disconnection of which made tumor avascular. Initially, intratumoral decompression followed by microsurgical total excision of tumor has been done. Tumor was nowhere attached to any of the surrounding structure. Postoperative period was uneventful. He did not develop any hearing disturbance or lower cranial nerves symptoms like hoarseness or dysphagia and recovered well. He had minimal left cerebellar signs as before. He was discharged on 10th post-operative day. Postoperative CT scan showed complete excision of tumor [] with residual edema in middle cerebellar peduncle. Histopathological examination confirmed the features of schwannomas [].