Abstract

Introduction

A tumor with EWSR1/FLI fusion displaying extensive well differentiated neuroblastomatous differentiation is presented.

Case report

A nine-year-old female patient had a thoracic vertebra 8 paraspinal mass. The lesion was resected incompletely. Histopathologically, a small round cell tumor with gangliomatous differentiation was seen. This was initially diagnosed as an intermixed ganglioneuroblastoma. In the completion surgery biopsy material, the small round cell component was more prominent. Immunohistochemistry for both samples showed membrane positivity for CD99 and nuclear positivity for NKX2.2 in the small round cell component of the tumor. Molecular analysis revealed EWSR1/FLI fusion. The diagnosis then considered a “Ewing Sarcoma Displaying Extensive Well Differentiated Neuroblastomatous Differentiation”.

Conclusion

Tumors with the EWSR1/FLI fusion may show neuroblastomatous differentiation. We chose to treat this as an Ewing Sarcoma (ES). Recognition of this phenomenon in ES cases may prevent a possible misinterpretation and a failure in oncologic treatment.

中文翻译：

---

尤文肉瘤显示广泛分化良好的神经母细胞瘤分化：一例报告

摘要

介绍

提出了一种具有 EWSR1/FLI 融合的肿瘤，显示出广泛的分化良好的神经母细胞瘤分化。

案例报告

患者女，9 岁，胸椎 8 椎旁肿块。病灶未完全切除。组织病理学上，可见一个具有神经节瘤样分化的小圆细胞肿瘤。这最初被诊断为混合性神经节细胞瘤。在完成手术活检材料中，小圆细胞成分更为突出。两个样本的免疫组织化学显示肿瘤的小圆细胞成分中 CD99 的膜阳性和 NKX2.2 的核阳性。分子分析显示 EWSR1/FLI 融合。然后诊断认为是“尤文肉瘤显示广泛分化良好的神经母细胞瘤分化”。

结论

具有 EWSR1/FLI 融合的肿瘤可能显示成神经母细胞瘤分化。我们选择将其视为尤文肉瘤 (ES)。识别 ES 病例中的这种现象可以防止可能的误解和肿瘤治疗的失败。