Purpose

The purpose is to highlight the primary intracranial (meningeal-based) occurrence of Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET).

Methods

This report is a collation of clinicopathological features of eight cases of molecularly and clinicoradiologically confirmed primary (non-metastatic) intracranial (non-osseous) meningeal ES/PNET.

Results

The age range was 1 to 33 years with a median age of 9 years. Male to female ratio was 0.6:1. All patients were diagnosed on the debulking surgical material (gross total resection, 2 cases; subtotal resection, 6 cases) and showed primitive embryonal histomorphology with diffuse membranous CD99 immunoexpression and EWSR1 gene rearrangement by fluorescence in situ hybridization. Seven of them showed a typical FISH pattern of split signals with break-apart probe, while one showed an unusual signal pattern of loss of green signals. EFT-2001 adjuvant protocol was followed along with focal radiotherapy (RT) in all cases (except case 8, full course of chemotherapy could not be completed). Two cases had local recurrence—one of them died of disease recurrence before the administration of further treatment.

Conclusion

This series adds non-osseous intracranial site to the list of uncommon sites of occurrence for ES/PNET and more importantly emphasizes the need to be considered in a differential list of primary intracranial primitive embryonal tumors before embarking as primary central nervous system (CNS) embryonal tumor, NOS.

中文翻译：

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原发性颅内尤文氏肉瘤/周围原始神经外胚层肿瘤，不认识的实体：一系列8例。

目的

目的是强调尤因肉瘤/原始神经外胚层肿瘤（ES / PNET）在颅内（​​基于脑膜）的发生。

方法

该报告整理了8例经分子和临床放射学证实的原发性（非转移性）颅内（非骨性）脑膜ES / PNET的临床病理特征。

结果

年龄范围为1至33岁，中位年龄为9岁。男女比例为0.6：1。所有患者均被诊断为体质减低的手术材料（大体全切除，2例；次全切除，6例），并表现出原始的胚胎组织形态，弥漫性膜CD99免疫表达和EWSR1基因通过荧光原位杂交重排。其中有七个显示了带有分离探针的分裂信号的典型FISH模式，而一个显示了绿色信号丢失的异常信号模式。在所有情况下，都遵循EFT-2001辅助方案以及局灶放疗（RT）（除了情况8，无法完成整个疗程）。有2例发生局部复发-其中1例在给予进一步治疗之前死于疾病复发。

结论

本系列文章将非骨性颅内部位添加到ES / PNET的罕见发生部位列表中，更重要地强调了在着手作为原发性中枢神经系统（CNS）胚胎之前应考虑在原发性颅内原始胚胎肿瘤的不同清单中进行考虑肿瘤，NOS。