Spinal intramedullary schwannoma: Report of two cases with review of the literature.

[INTRODUCTION] Spinal tumors comprise 15 % of all central nervous system tumors, with schwannomas accounting for 30 % of primary intraspinal neoplasms. While predominantly extramedullary-intradural, spinal schwannomas rarely manifest intramedullary occurrences (0.3 % of intraspinal tumors). This study sheds light on two rare cases of thoracic intramedullary schwannomas, emphasizing their diagnostic complexities and surgical management, alongside a literature review.

[CASE PRESENTATION] Case 1 involves a 50-year-old female presenting with worsening back pain, right lower limb weakness, and urinary incontinence. MRI revealed an intradural intramedullary soft tissue mass, diagnosed as a schwannoma with an associated organizing hematoma. Surgical removal led to gradual improvement. Case 2 features a 25-year-old male with back pain, partial foot drop, and weakness in the right knee and hip. MRI demonstrated an intradural intramedullary lesion, later confirmed as an intradural intramedullary schwannoma. Surgery resulted in a smooth recovery without adverse effects.

[DISCUSSION] This article presents two cases of intradural intramedullary thoracic schwannomas initially misdiagnosed as astrocytomas. Surgical resection confirmed the diagnosis, underscoring challenges in preoperative MRI diagnosis. The review of 174 reported cases reveals an equal distribution between the cervical and thoracic regions, with males affected 1.5 times more frequently than females. The average age of onset is 40, and surgical treatment demonstrates a 90 % improvement rate. The complex pathogenesis encompasses six proposed explanations. Clinical suspicion, considering pain and neurological symptoms, is paramount due to potential misdiagnosis and the imperative for histological confirmation.

[CONCLUSION] Although rare, intramedullary schwannomas (IMS) have significant clinical implications, necessitating precise treatment. Surgical resection yields favorable outcomes, with subtotal resection considered based on adhesion factors. Pre-surgical diagnosis requires a comprehensive integration of radiological and clinical data, with intraoperative analysis ensuring optimal treatment strategies.