Thoracic meningocele in patients with neurofibromatosis type 1: A review of literature with illustration of a novel surgical challenge, and insights from histology

Abstract

Background: 69% of thoracic meningoceles are associated with Neurofibromatosis type 1(NF1). Pathology is debated between being a saccular protrusion of dysplastic meninges through a vertebral defect, or a forme fruste of neurofibroma, with no pathological evidence to the later. Treatment is usually conservative, however surgical intervention is sometimes indicated. Surgical options include thoracotomy, endoscopic plication of the cyst, or CSF diversion. After excision of the meningocele, watertight closure of the dura is difficult and meningoceles often reform, so dural reinforcement is indicated. Objective: A literature review on thoracic meningocele in NF1 patients: pathological hypothesis, presentation including rupture and hemothorax in large meningoceles, management strategies, and surgical challenges. The review also includes an illustrative case discussing the surgical challenges with giant meningoceles.Case presentation.A 46 year old male, NF1, with a known thoracic meningocele, presented with dyspnoea due to enlarging thoracic meningocele. The meningocele was successfully excised via thoracotomy in a challenging surgery with a novel surgical technique and unique insight on histology. Results: 10 cases of giant meningoceles in NF1 patients have been reported in literature, surgery was performed in 9 of them. 1 patient died, and there was recurrence or no change in 6 them. Histology in our illustrative case showed diffuse population of schwann cells. Also, Buttress plates achieved reinforced dural closure with no recurrence. Conclusion: Our study concluded that in in large thoracic meningocele(s) surgery via thoracotomy is advised , and dural reinforcement with buttress plates proved to be successful. Our study also concluded that meningoceles in NF1 patients is likely a forme fruste of neurofibroma, or a giant cystic neurofibroma rather than due to dysplastic dura.