Spinal subependymoma mimicking an intradural extramedullary tumor: illustrative case.
- 1Department of Neurosurgery, Aichi Medical University, Nagakute, Aichi.
- 2Department of Diagnostic Pathology, Aichi Medical University, Nagakute, Aichi, Japan.
Abstract
Background
Spinal subependymomas are rare, benign tumors that typically arise within the spinal cord and usually appear as intramedullary lesions on MRI. The authors report a rare case of cervical spinal subependymoma with exophytic growth that mimicked an intradural extramedullary tumor on MRI.Observations
A 53-year-old man presented with right-sided paresthesia. MRI revealed a spinal tumor causing marked spinal cord compression. The lesion was isointense on T1-weighted images, slightly hyperintense on T2-weighted images, and showed no gadolinium enhancement. A focal CSF cleft between the tumor and spinal cord led to a preoperative diagnosis of an intradural extramedullary tumor, and schwannoma was suspected. However, intraoperative pathological examination suggested a low-grade glioma, prompting a change in the surgical strategy. Subtotal resection was therefore performed to preserve neurological function. Histological examination subsequently confirmed the diagnosis of subependymoma.Lessons
Spinal subependymoma may rarely present with an apparent intradural extramedullary appearance on MRI. The presence of a CSF cleft and exophytic growth should not exclude an intramedullary origin. Awareness of this atypical presentation and avoidance of anchoring bias are essential for appropriate intraoperative decision-making. When subependymoma is suspected, maximal safe resection should be prioritized over aggressive tumor removal to preserve neurological function. https://thejns.org/doi/10.3171/CASE26728.
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BibTeX
@article{inomo2026spinal,
title = {{Spinal subependymoma mimicking an intradural extramedullary tumor: illustrative case.}},
author = {Toshiaki Inomo and Toshiki Fukuoka and Masahito Hara and Ryuya Maejima and Risa Oishi and Koji Osuka and Tadashi Watanabe},
journal = {Journal of neurosurgery. Case lessons},
year = {2026},
month = oct,
doi = {10.3171/case26728},
url = {https://europepmc.org/article/MED/42896231},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Spinal subependymoma mimicking an intradural extramedullary tumor: illustrative case.
AU - Toshiaki Inomo
AU - Toshiki Fukuoka
AU - Masahito Hara
AU - Ryuya Maejima
AU - Risa Oishi
AU - Koji Osuka
AU - Tadashi Watanabe
PY - 2026
DA - 2026/10/19
JO - Journal of neurosurgery. Case lessons
DO - 10.3171/case26728
UR - https://europepmc.org/article/MED/42896231
AB - Background Spinal subependymomas are rare, benign tumors that typically arise within the spinal cord and usually appear as intramedullary lesions on MRI. The authors report a rare case of cervical spinal subependymoma with exophytic growth that mimicked an intradural extramedullary tumor on MRI.Observations A 53-year-old man presented with right-sided paresthesia. MRI revealed a spinal tumor causing marked spinal cord compression. The lesion was isointense on T1-weighted images, slightly hyperintense on T2-weighted images, and showed no gadolinium enhancement. A focal CSF cleft between the tumor and spinal cord led to a preoperative diagnosis of an intradural extramedullary tumor, and schwannoma was suspected. However, intraoperative pathological examination suggested a low-grade glioma, prompting a change in the surgical strategy. Subtotal resection was therefore performed to preserve neurological function. Histological examination subsequently confirmed the diagnosis of subependymoma.Lessons Spinal subependymoma may rarely present with an apparent intradural extramedullary appearance on MRI. The presence of a CSF cleft and exophytic growth should not exclude an intramedullary origin. Awareness of this atypical presentation and avoidance of anchoring bias are essential for appropriate intraoperative decision-making. When subependymoma is suspected, maximal safe resection should be prioritized over aggressive tumor removal to preserve neurological function. https://thejns.org/doi/10.3171/CASE26728.
SN - 2694-1902
ER -