Sharma S, Abbott R I, Zagzag D
Department of Pathology, New York University Medical Center, New York 10016, USA.
Cancer. 1998 Feb 1;82(3):545-52.
Intraparenchymal nerve sheath tumors of the central nervous system are rare, usually benign tumors. Three cases with tumor recurrences have previously been reported in the literature. The authors report a case of a malignant intracerebral nerve sheath tumor in a girl age 8 years and analyze the biologic characteristics of this tumor.
The tumor was analyzed by histologic, immunohistochemical, and ultrastructural techniques.
Magnetic resonance imaging revealed a mixed, attenuating, contrast-enhancing mass in the right posterior temporal lobe. Histopathology of the resected specimen revealed a uniformly S-100 positive and reticulin rich biphasic tumor with a characteristic distribution of spindle and epithelioid cells, with the latter almost entirely confined to the invading edge of the tumor. There was extensive brain infiltration in the form of lobules and fingerlike processes with a targetoid appearance. The spindle cells showed palisading and had elongated, wavy nuclei. Electron microscopy demonstrated basal lamina around both cell types with scattered Luse bodies in between. The patient is perfectly healthy and recurrence free 17 months after surgery.
This represents the fourth and the youngest case in the literature of a malignant intracerebral nerve sheath tumor and highlights the distinctive clinicopathologic features of these tumors. First, these tumors have very great infiltrative potential, as observed histopathologically and reflected in their frequent recurrences. Second, epithelioid cells confined to the infiltrative edge suggest their aggressive role. Epithelioid cells have been shown to represent a malignant component of systemic schwannomas with malignant transformation; however, this case does not have any evidence of origin from a preexisting benign schwannoma. Third, despite histologic similarities to neuraxial desmoplastic neuroepithelial tumors, none of the malignant schwannomas had any evidence of divergent differentiation towards astrocytic or neuronal lineage, and had a much worse prognosis. Fourth, the event free survival after initial resection appears to be an important predictor of overall survival in the reviewed cases. Chemotherapy and radiation therapy have not been successful in the treatment of this rare entity. Hence, an accurate diagnosis and planned extensive resection appear to be the key elements in its management.
中枢神经系统实质内神经鞘瘤罕见，通常为良性肿瘤。此前文献中曾报道过3例肿瘤复发的病例。作者报告了1例8岁女孩的恶性脑内神经鞘瘤病例，并分析了该肿瘤的生物学特征。
采用组织学、免疫组织化学和超微结构技术对肿瘤进行分析。
磁共振成像显示右侧颞叶后部有一个混合性、衰减性、增强性肿块。切除标本的组织病理学显示为一种均匀的S-100阳性且富含网硬蛋白的双相肿瘤，具有特征性的梭形细胞和上皮样细胞分布，后者几乎完全局限于肿瘤的浸润边缘。存在广泛的脑浸润，呈小叶状和指状突起，具有靶样外观。梭形细胞呈栅栏状排列，细胞核细长、呈波浪状。电子显微镜显示两种细胞类型周围均有基膜，其间有散在的卢斯小体。患者术后17个月完全健康，无复发。
这是文献中第四例也是最年轻的恶性脑内神经鞘瘤病例，突出了这些肿瘤独特的临床病理特征。第一，如组织病理学所见并反映在其频繁复发中，这些肿瘤具有很强的浸润潜能。第二，局限于浸润边缘的上皮样细胞提示其具有侵袭性作用。上皮样细胞已被证明是系统性神经鞘瘤伴恶性转化的恶性成分；然而，该病例没有任何起源于先前存在的良性神经鞘瘤的证据。第三，尽管在组织学上与神经轴索促结缔组织增生性神经上皮肿瘤相似，但恶性神经鞘瘤均无向星形细胞或神经元谱系分化的证据，且预后更差。第四，在回顾的病例中，初次切除后的无事件生存期似乎是总生存期的重要预测指标。化疗和放疗对治疗这种罕见疾病均未成功。因此，准确诊断和计划性广泛切除似乎是其治疗的关键要素。
