BACKGROUND Spinal schwannoma is a common benign tumor. However, the high recurrence rate and incidence of surgical complications are unsolved problems. OBJECTIVE To propose a morphological classification of spinal schwannoma based on tumor-membrane relationships to increase the gross total resection (GTR) rate and to decrease the incidence of surgical complications. METHODS Histological techniques were used to study 7 adult cadavers. Following picrosirius staining, the membranes around the nerve root were observed under a microscope. Data from 101 patients with spinal schwannoma were also collected for clinical analysis. RESULTS The sleeve around the spinal nerve root consisted of dura and arachnoid tissues. The space between them gradually narrowed and fused at the proximal pole of the nerve root ganglion. Spinal schwannomas were divided into 4 types based on membranous structure: intrapial (type I), subarachnoidal (type II), intra- and extradural (type III), and extradural growth (type IV). Types II and III were further subdivided into 2 subtypes. GTR was achieved in all patients (100%), with no tumor recurrence during follow-up. Overall functional status significantly improved postoperatively. A total of 59 patients (92%) showed improvement or significant improvement postoperatively. There was no difference in surgical outcomes among the tumor classifications (P = .618). No intraoperative vertebral artery injuries or postoperative cerebrospinal fluid fistula occurred. CONCLUSION Spinal schwannoma classification based on a membranous hierarchy provides an intuitive platform for preoperative planning and intraoperative safety. This classification scheme may help surgeons better define surgical goals and anticipate or even avoid complications from resection.

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基于膜层次结构的脊髓神经鞘瘤新分类及其临床意义

背景脊髓神经鞘瘤是一种常见的良性肿瘤。然而，高复发率和手术并发症的发生率是悬而未决的问题。目的提出一种基于瘤膜关系的脊髓神经鞘瘤形态学分类，以提高总切除率（GTR）并降低手术并发症的发生率。方法采用组织学技术研究7具成年尸体。天狼星染色后，在显微镜下观察神经根周围的膜。还收集了 101 名脊髓神经鞘瘤患者的数据用于临床分析。结果脊神经根周围的套管由硬脑膜和蛛网膜组织组成。它们之间的空间逐渐变窄并在神经根神经节的近端融合。脊髓神经鞘瘤根据膜结构分为4种类型：膜内（I型）、蛛网膜下（II型）、硬膜内和硬膜外（III型）和硬膜外生长（IV型）。II型和III型进一步细分为2个亚型。所有患者 (100%) 均达到 GTR，随访期间无肿瘤复发。术后整体功能状态明显改善。共有 59 名患者（92%）在术后出现改善或显着改善。不同肿瘤分类的手术结果没有差异（P = .618）。无术中椎动脉损伤及术后脑脊液瘘发生。结论基于膜层的脊髓神经鞘瘤分类为术前计划和术中安全提供了一个直观的平台。