Symptomatic intramedullary arachnoid cyst: Case report and literature review

Intramedullary arachnoid cysts (IMACs) are exceptionally rare entities, posing diagnostic and therapeutic challenges owing to their rarity and potential for severe neurological sequelae. Early diagnosis combined with timely surgical intervention is critical for favorable outcomes. Although postoperative recovery is often satisfactory, the risk of recurrence necessitates long-term follow-up. We report the case of an 11-year-old boy presenting with progressive dorsal spine pain and lower limb weakness. Neurological examination revealed paraplegia with hyperreflexia and preserved sensation. MRI of the spine revealed an intramedullary cystic lesion extending from C7 to T2. Emergency microsurgical decompression was performed through a posterior approach with midline myelotomy. Intraoperatively, a cystic lesion adherent to the spinal cord parenchyma was identified and partially resected. Postoperative recovery was favorable, with improvement in motor function and regression of the cystic lesion on follow-up MRI. Histopathological examination confirmed the diagnosis of an arachnoid cyst. This case highlights key aspects of clinical presentation, diagnostic strategies, and surgical management, and contributes to the growing literature on this rare entity.