Spinal extradural arachnoid cyst

Summary Spinal extradural arachnoid cysts are rare expanding lesions in the spinal canal. They usually present with progressive signs and symptoms caused by spinal cord compression if they enlarge. A comprehensive review about spinal extradural arachnoid cyst is made including the author’s own case of a 59-year-old woman with a 6-month history of progressive back pain radiating to both legs. Key points concerning the possible pathogenesis including symptomatology, diagnosis, and the implications for treatment are highlighted. Surgical treatment is curative and this rare clinical entity should be considered in the differential diagnosis of spinal extradural lesions.     

Spinal Arachnoid Web: A didactic report of two cases with clinical,radiological, surgical and pathological correlations

BackgroundArachnoid web (AW) is a rare but probably underestimated cause of spinal cord injury that is complex to diagnose due to subtle MRI findings and similarities to other better-known diseases such as arachnoid cyst (AC) or transdural spinal cord herniation (TSCH). Increased recognition of AW is mandatory since delay in diagnosis can lead to potentially serious neurological sequelae.Case presentationsWe report two additional cases of AW for didactic purposes, with special emphasis on the distinctive MRI and intraoperative findings. Both patients presented with progressively worsening neurological symptoms, including proprioceptive ataxia, motor weakness, numbness and neuropathic pain. The diagnosis of AW was suspected on the basis of specific MRI criteria, especially the so-called “scalpel sign”. Formal confirmation of the diagnosis was obtained in two patients that were managed surgically. Postoperative follow-up demonstrated significant functional recovery.DiscussionThere is a need for better recognition of AW by the medical community. Careful analysis of MRI semiology is crucial for the distinction between AW, AC and TSCH. Prompt and accurate diagnosis is mandatory to conserve functional prognosis, since appropriate surgical treatment with AW resection is curative, halting or even resolving the neurological symptoms.