Abstract：
The WHO Classification of Soft Tissue and Bone Tumours currently recognizes four categories of undifferentiated small round cell sarcoma: Ewing sarcoma, round cell sarcoma with EWSR1-non-ETS fusions including NFATc2 and PATZ1, CIC-rearranged sarcoma, and sarcoma with BCOR genetic alterations. These neoplasms frequently pose significant diagnostic challenges due to rarity and overlapping morphologic and immunohistochemical findings. Further, molecular testing, with accompanying pitfalls, may be needed to establish a definitive diagnosis. This review summarizes the clinical, histologic, immunohistochemical, and molecular features of these neoplasms. In addition, differential diagnosis and areas of uncertainty and ongoing investigation are discussed.
摘要：
WHO对软组织和骨肿瘤的分类目前承认四类未分化的小圆细胞肉瘤：尤因肉瘤，EWSR1-非ETS融合的圆形细胞肉瘤，包括NFATc2和PATZ1，CIC重排肉瘤，和BCOR基因改变的肉瘤。由于稀有和重叠的形态学和免疫组织化学发现，这些肿瘤通常会带来重大的诊断挑战。Further,分子检测,伴随着陷阱，可能需要建立明确的诊断。本文综述了临床、组织学，免疫组织化学，和这些肿瘤的分子特征。此外,讨论了鉴别诊断和不确定性领域以及正在进行的调查。
