Microsurgical Resection of a Fourth Ventricular Ependymoma With Cervical Extension
A 3.5 cm fourth ventricular ependymoma extended through the obex into the upper cervical canal and caused obstructive hydrocephalus. A telovelar fourth ventricle approach combined with suboccipital craniotomy and C1 laminectomy provided access across the tumor's full cranio-caudal extent while prioritizing brainstem and lower cranial nerve preservation.
A fourth ventricle tumor extending beyond the skull into the cervical canal
A 28-year-old man presented with a three-month history of progressive occipital headaches, neck pain, nausea and vomiting. During the final week, his symptoms worsened significantly. Neurologic examination demonstrated truncal ataxia, dysmetria on finger-to-nose testing and horizontal nystagmus, without cranial nerve deficits, motor weakness or sensory abnormalities.
Brain MRI demonstrated a 3.5 cm heterogeneously enhancing lesion centered within the fourth ventricle, extending caudally through the obex into the upper cervical canal at C1–C2. The mass caused obstructive hydrocephalus with an Evans index of 0.35. T1-weighted imaging showed a predominantly hypointense lesion with cystic components; T2/FLAIR sequences demonstrated hyperintensity with mild surrounding edema.
Because ependymomas can disseminate through cerebrospinal fluid pathways, staging included total-spine MRI and CSF cytology. There was no evidence of drop metastases or spinal seeding, and CSF cytology was negative for malignant cells.
Why a telovelar fourth ventricle approach?
The surgical goal was gross total resection with maximal neuroprotection. The tumor's relationship to the floor of the fourth ventricle and its extension through the obex into the upper cervical canal required an operative corridor that provided direct inferior access while minimizing unnecessary disruption of normal neural tissue.
A midline suboccipital craniotomy with C1 laminectomy expanded the inferior operative trajectory to the cerebellomedullary cistern, cervicomedullary junction and proximal cervical canal. Rather than splitting the cerebellar vermis, the telovelar approach opened the cerebellomedullary fissure and used normal anatomical planes to enter the fourth ventricle.
The tela choroidea and inferior medullary velum were carefully opened to expose the inferior fourth ventricle, obex and tumor margins. Internal tumor debulking reduced mass effect, followed by circumferential microsurgical dissection along the tumor–neural interface while preserving critical brainstem pathways.
The technical goal
Create direct access to the full cranio-caudal extent of the tumor while preserving the floor of the fourth ventricle, brainstem pathways and lower cranial nerve function. C1 laminectomy improved the inferior working angle for the cervical component, while telovelar access avoided direct splitting of midline cerebellar tissue.
From obstructive mass effect to gross total resection
Preoperative and postoperative contrast-enhanced MRI demonstrate the fourth ventricular tumor, its caudal extension and the result after microsurgical resection.
with preservation of
neurological function.
Postoperative MRI confirmed gross total resection with no residual enhancing tumor. The patient experienced transient dysphagia that resolved by postoperative day three and mild truncal ataxia that improved with rehabilitation.
He was discharged on postoperative day seven with outpatient physical therapy. Given the low-grade pathology and confirmed complete resection, the multidisciplinary recommendation was observation with structured surveillance imaging rather than immediate adjuvant therapy.
Complete removal has to be balanced against brainstem and cranial nerve preservation
For fourth ventricular ependymomas, extent of resection is an important modifiable factor in long-term tumor control. The challenge is that the surgical objective sits immediately beside structures governing swallowing, vocal cord function, breathing coordination and long-tract motor pathways.
In this case, the operative strategy was designed to maximize the likelihood of complete tumor removal while preserving the brainstem and lower cranial nerves. Because delayed recurrence and rare CSF dissemination can occur even after gross total resection, long-term surveillance imaging remains important.
Low-grade pathology supported surveillance after complete resection
Histopathology confirmed a WHO Grade I ependymoma with classic features including perivascular pseudorosettes and low mitotic activity. Molecular profiling was favorable, with no RELA fusion and preserved H3K27me3 expression.
With no residual enhancing tumor on postoperative MRI and low-grade pathology, the multidisciplinary recommendation was observation with structured surveillance rather than immediate additional treatment.
Yaron A. Moshel, MD, PhD
Dr. Yaron Moshel is President of Atlantic Brain and Spine, Chair of Neurosurgery at Morristown Medical Center and Director of the Brain Tumor Center. His practice focuses on complex brain and skull base tumors, including microsurgical approaches designed around tumor anatomy and preservation of neurological function.
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