A rare case of multi-segmental lumbar intradural ependymoma: clinical presentation and surgical management: a case...

Intradural extramedullary(IDEM)-type Ependymoma is a rare clinicalentity belonging to the broader category of uncommon glial neoplasms. To date, most published studies have focused predominantly on classic anatomical locations-particularly the filum terminale, whereas the present case arose from an atypical spinal site, highlighting the pronounced anatomical heterogeneity characteristic of this tumor subtype. Moreover, its neuroimaging features demonstrate considerable overlap with those of more common intraspinal tumors, including schwannomas and meningiomas, thereby presenting a substantial diagnostic challenge and elevating the risk of misdiagnosis.increasing the risk of misdiagnosis.

30-year-old male patient underwent contrast-enhanced lumbar MRI, which revealed a hypervascular intradural tumor spanning the L1-L3 vertebral levels. Complete surgical resection was achieved; the resected specimen measured 4.5 cm×2.5 cm×1.0 cm. Postoperative histopathological examination confirmed the diagnosis of spinal ependymoma. Spinal ependymomas most commonly arise in the filum terminale region, where they are typically amenable to gross-total resection with a relatively low risk of permanent neurological deficit. In this case, however, the tumor was located at the L1-L3 level,a region densely populated by motor neurons and autonomic nerve fibers innervating the lower limbs and pelvic viscera. Consequently, the tumor posed a heightened risk of infiltration into adjacent nerve roots or spinal cord parenchyma. Differential diagnosis:(1) Schwannoma. On MRI, schwannomas are typically iso- to hypointense on T1-weighted images and hyperintense on T2-weighted images. Cystic degeneration is common, and contrast-enhanced imaging generally demonstrates enhancement of the solid component, particularly in Antoni A-predominant areas, whereas cystic regions remain non-enhancing. Intradural extramedullary (IDEM) ependymomas may likewise appear iso- to hypointense on T1-weighted images and iso- to hyperintense on T2-weighted images; however, cystic change, hemorrhage, and heterogeneous enhancement of the solid component may be more prominent. Both lesions can produce neural compression and pain, although radicular pain is more characteristic of schwannoma because of its frequent origin from a spinal nerve root.(2) Spinal meningioma. Spinal meningiomas occur predominantly in middle-aged women and usually appear as well-circumscribed round, oval, or plaque-like intradural extramedullary masses. They are commonly isointense on both T1- and T2-weighted images and demonstrate strong, usually homogeneous enhancement, often accompanied by a dural tail sign. Clinical manifestations may include localized back pain, radicular pain, gait disturbance, and sensory impairment. In contrast, IDEM ependymomas arising in the conus medullaris-cauda equina region may present with more diffuse pain, bilateral lower-extremity weakness, sensory disturbances, or sphincter dysfunction, including urinary retention.(3) Lipoma.Spinal lipomas typically demonstrate homogeneous high signal intensity on T1-weighted images, with complete signal suppression on fat-saturated sequences and little or no contrast enhancement. They are more frequently associated with congenital spinal abnormalities and are commonly detected in children or young patients.(4) Metastatic disease. Spinal ependymomas are generally solitary intradural lesions, often involving the conus medullaris, filum terminale, or cauda equina region, and usually show enhancement of the solid tumor component. By contrast, spinal metastases occur more commonly in older patients and are often associated with a known primary malignancy. Imaging may demonstrate multifocal or noncontiguous vertebral marrow replacement, low signal intensity on T1-weighted images, contrast enhancement, cortical destruction, and possible epidural or paraspinal extension. Nevertheless, intradural metastasis should also be considered when a patient has a history of systemic cancer or evidence of disseminated disease.

This case report describes a rare multi-segmental lumbar intradural extramedullary ependymoma located at the atypical L1-L3 spinal levels, emphasizing the diagnostic and therapeutic challenges associated with non-classical anatomical presentations. Unlike the more commonly reported filum terminale ependymomas, tumors arising in the upper lumbar region are closely related to cauda equina nerve roots, motor pathways, and autonomic neural structures, thereby requiring a surgical strategy that balances maximal tumor resection with preservation of neurological function. In line with current international perspectives, contrast-enhanced MRI should be regarded as the first-line modality for preoperative localization, assessment of tumor enhancement patterns, and evaluation of its relationship with adjacent neural structures; however, definitive diagnosis still depends on integrated histopathological, immunohistochemical, and molecular evaluation. In the present case, gross-total resection was achieved with preservation of neurological function, and no evidence of recurrence was observed during follow-up, supporting the view that surgery remains the cornerstone of treatment for low-grade spinal ependymoma, while adjuvant radiotherapy should be considered mainly in cases of subtotal resection, residual disease, recurrence, or higher-grade pathology. More importantly, this case highlights the need to overcome location-based diagnostic bias, include ependymoma in the differential diagnosis of atypical lumbar intradural extramedullary tumors, and adopt a multidisciplinary, function-preserving, precision-based management strategy. Long-term radiological surveillance remains essential because recurrence may occur even after apparently complete resection. Therefore, this report provides clinically relevant evidence for improving recognition, individualized surgical planning, and postoperative follow-up strategies for rare lumbar IDEM ependymomas.