Spinal ependymoma mimicking longitudinally extensive transverse myelitis: A case report

Longitudinally extensive transverse myelitis (LETM) refers to spinal cord involvement extending across three or more vertebral segments and is most commonly associated with inflammatory or infectious etiologies. Among the most frequent causes are neuromyelitis optica spectrum disorders (NMOSD) and granulomatous infections such as tuberculosis. However, although less common, certain low-grade intramedullary tumors such as spinal ependymomas may present with clinical and radiological features that mimic LETM, making diagnosis more challenging and potentially delaying appropriate management.

We report the case of a 17-year-old female admitted for ascending paralysis and respiratory distress. Initial spinal MRI revealed a cervico-thoracic intramedullary lesion hypointense on both T1- and hyperintense T2- weighted sequences, with peripheral contrast enhancement, along with an intradural extramedullary mass at the D11-D12 level, initially suggestive of an inflammatory or infectious origin. Due to the lack of clinical improvement following high-dose corticosteroid therapy and plasmapheresis, a follow-up MRI was performed. It demonstrated partial regression of the intramedullary abnormalities but a significant increase in the size of the extramedullary mass, now exerting a compressive effect on the spinal cord and suggesting secondary meningeal involvement. The lesion’s well-defined and progressive radiological appearance raised suspicion for a neoplastic origin. Surgical biopsy and subsequent histopathological analysis confirmed the diagnosis of a low-grade spinal ependymoma.

This case highlights the importance of including tumoral etiologies in the differential diagnosis of LETM, particularly in cases with poor therapeutic response or atypical clinical evolution. Radiological monitoring and histopathological confirmation remain critical for establishing an accurate diagnosis and ensuring timely, appropriate treatment.