Radiological, Histopathological, and Surgical Outcomes of Intradural Spinal Ependymomas: A Single-Center Retrospective Series.

Abstract

Spinal ependymomas are the most common primary intramedullary spinal tumors in adults, yet significant heterogeneity exists in their anatomical location, histopathology, and surgical outcomes. Conventional classification into intramedullary and extramedullary subtypes may oversimplify clinically relevant differences. This study aimed to evaluate the radiological, histopathological, and surgical outcomes of spinal intradural ependymomas using a practical anatomical framework based on true spinal cord, conus medullaris, and filum terminale subgroups. We retrospectively analyzed 42 patients who underwent surgical treatment for histopathologically confirmed spinal intradural ependymomas between 2015 and 2025 at a single tertiary center. Demographic, radiological, histopathological, surgical, and functional outcome data were collected. Neurological function was assessed using the Modified McCormick Scale (MMcCS). Comparative analyses were performed across the three anatomical subgroups. Median age was 40 years, with slight female predominance (55%). Pain was the most common presenting symptom (88%). Gross total resection was achieved in 93% of cases. Most tumors were WHO grade 2 (90%), and myxopapillary ependymomas were predominantly located in the filum terminale and lower lumbar region. Neurological function remained stable or improved in 81-83% of patients throughout follow-up. Significant subgroup differences were identified in sensory deficits, tumor width, EMA expression, and functional outcomes. True cervical/thoracic spinal cord tumors demonstrated worse preoperative neurological status and less favorable long-term recovery, whereas filum terminale tumors showed the most favorable outcomes. Conus medullaris tumors displayed intermediate clinical and functional characteristics. Leptomeningeal seeding occurred in 7% of patients and was associated with elevated Ki-67 indices. Spinal intradural ependymomas exhibit substantial anatomical and functional heterogeneity. Tumor location strongly influences clinical presentation, surgical complexity, and neurological outcomes. Conus medullaris ependymomas demonstrate intermediate behavior between spinal cord and filum terminale tumors, supporting their consideration as a distinct clinical subgroup.