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BACKGROUND: Arachnoid cysts are often congenital, asymptomatic lesions detected in the pediatric population. When seen in adults, they usually occur following trauma. De novo formation of arachnoid cysts is uncommon, with only a few instances cited in the literature and most of which occurred in the pediatric population. Treatment options for these lesions include observation, craniotomy for cyst resection, microsurgical/endoscopic fenestration, or shunting. OBSERVATIONS: In this report, the authors describe a female patient with a de novo, symptomatic, enlarging middle cranial fossa arachnoid cyst detected at age 16 years. She was treated with the placement of a cystoperitoneal shunt. After surgery, she experienced clinical and radiological improvement. LESSONS: We illustrate successful shunting of a de novo arachnoid cyst in a symptomatic teen patient. Although arachnoid cysts in certain intracranial locations are more likely to produce symptoms, those in the middle cranial fossa tend to be asymptomatic. To our knowledge, this is the first reported case of a symptomatic de novo arachnoid cyst located in the middle cranial fossa in a postpubertal patient. Although the current presentation is rare, the authors demonstrate an effective surgical treatment of a symptomatic, large, de novo arachnoid cyst in a postpubertal pediatric patient.
RESUMO
BACKGROUND AND OBJECTIVES: Current surgical strategies for dumbbell nerve sheath tumors (DNSTs) with cord compression have primarily involved wide spinal exposures with total laminectomy and unilateral facetectomy, often leading to spinal destabilization and requiring fusion, or staged procedures separately addressing the intraspinal and extraforaminal tumor components. This study highlights technical nuances of a novel approach for DNST resection to minimize spinal destabilization and avoid fusion while facilitating safe, single-stage complete resection. METHODS: A retrospective chart review was conducted on patients undergoing DNST resection. Using unilateral subperiosteal dissection, hemilaminotomy and medial facetectomy procedures are performed. The extradural tumor component is resected, followed by internal decompression of the intradural tumor. A small horizontal incision at the origin of the nerve root sleeve releases the underlying dural stricture, facilitating delivery of the remaining intradural tumor and allowing section of the nerve root of origin. Ultrasonography confirms complete tumor resection and return of cord pulsation, and excludes intradural hemorrhagic complications. The dura is reconstructed using a dural substitute bolstered with fat graft and sealant. RESULTS: Twelve consecutive patients undergoing this approach from 2014 to 2021 were included. Mean patient age was 53.5 years, and 58.3% were male. Nine tumors were cervical and 3 were lumbar. Five patients presented with myelopathy, 4 with radiculopathy, and 4 with axial pain. Two cases had transient intraoperative neuromonitoring signal changes. Eleven tumors were diagnosed as schwannomas and 1 as neurofibroma. All patients had complete resection of the intraspinal component; 2 had far distal extraforaminal residual. No patient has had recurrence, progression of residual, or signs of spinal instability during follow-up (median 28.5 months, range 6-66 months). CONCLUSION: This study highlights technical considerations for DNST resection, focusing the approach at the center of the tumor, with minimal bone removal and ligamentous disruption. Intraoperative ultrasound is instrumental in the safety of this approach.