Keisuke Onoda*, Takumi Kimura, Ryousuke Doi, Shunsuke Hatakenaka, Jumpei Kato, Tomihiro Wakamiya, Masahiro Indou, Kimihiro Nakahara, Tatsuya Tanaka, Takashi Agari, Takashi Suga- wara, Kazuaki Shimoji, Eiichi Suehiro, Hiroshi Itokawa and Akira Matsuno

Department of Neurosurgery, School of Medicine, International University of Health and Welfare, Narita Hospital, Narita, Japan

*Corresponding Author: Keisuke Onoda, Department of Neurosurgery, School of Medicine, International University of Health and Welfare, Narita Hospital, Narita, Japan.

Received: March 16, 2026; Published: April 28, 2026

Abstract

Background: Fourth ventricular ependymomas predominantly occur in children, and adult cases presenting with massive tumor size and acute hydrocephalus are uncommon. Surgical management is particularly challenging when tumors are adherent to the floor of the fourth ventricle, where aggressive resection may result in significant neurological morbidity. Recent molecular classification has further highlighted the heterogeneity of posterior fossa ependymomas.

Case Description: A 27-year-old man presented with a 1-month history of progressive headache and nausea, followed by impaired consciousness due to acute obstructive hydrocephalus. Imaging revealed a giant tumor, approximately 5 cm in diameter, occupying the entire fourth ventricle. Emergency external ventricular drainage resulted in rapid neurological improvement. Definitive tumor resection was subsequently performed via a midline suboccipital craniotomy using the telovelar approach. Although most of the tumor was safely removed, a small portion densely adherent to the floor of the fourth ventricle was intentionally preserved to avoid neurological injury. Postoperative contrast-enhanced MRI demonstrated no residual enhancing lesion. Histopathological examination revealed ependymoma with focal anaplastic features (WHO grade III). Molecular analysis showed predominantly posterior fossa group A (PFA) characteristics with focal posterior fossa group B components. Adjuvant radiotherapy (54 Gy) was administered. The postoperative course was uneventful, and the patient returned to his previous occupation without neurological deficits.

Conclusion: This case demonstrates that giant fourth ventricular ependymomas in adults, with predominantly PFA molecular features, can be effectively managed using a telovelar approach that prioritizes neurological safety, combined with appropriate adjuvant radiotherapy, resulting in favorable functional and oncological outcomes.

Keywords: Fourth Ventricular Ependymoma; Telovelar Approach; Hydrocephalus; Posterior Fossa Tumor

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Citation

Citation: Keisuke Onoda., et al. “Giant Fourth Ventricular Ependymoma Presenting with Acute Hydrocephalus in a Young Adult". Acta Scientific Neurology 9.5 (2026): 04-08.

Copyright

Copyright: ©2026 Keisuke Onoda., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.