Abstract Background: Spinal arachnoid cysts are rare, benign cerebrospinal fluid–filled lesions that may cause spinal cord or nerve root compression. They are most frequently located in the thoracic region and typically present with a slow, insidious clinical course. Case Description: We report the case of a 52-year-old man presenting with a 3-4-year history of progressive back pain and markedly reduced walking distance consistent with neurogenic claudication–like symptoms. Neurological examination was unremarkable, and lumbar Magnetic Resonance Imaging (MRI) failed to demonstrate explanatory pathology. Thoracic MRI revealed an intradural extramedullary cystic lesion at the T9–T10 level, causing anterior displacement of the spinal cord. The lesion was hypointense on T1-weighted and hyperintense on T2-weighted sequences and showed no contrast enhancement. The patient underwent thoracic laminectomy with complete cyst excision under intraoperative neuromonitoring. Histopathological analysis confirmed a benign arachnoid cyst. Postoperative MRI demonstrated complete decompression, and the patient experienced marked clinical improvement, remaining symptom-free at six-month follow-up. Conclusion: Thoracic intradural extramedullary arachnoid cysts may present with atypical symptoms mimicking lumbar spinal stenosis, even in the absence of neurological deficits. In patients with neurogenic claudication and normal lumbar imaging, evaluation of the thoracic spine should be considered. Early surgical decompression can result in excellent clinical outcomes.
AK et al. (2026) studied this question.