Abstract:
Objective: To investigate the clinicopathological, immunohistochemical and molecular features of small round cell sarcoma (SRCS) of the bone and soft tissue, and to compare the diagnostic value of different techniques. Methods: Seventy-two cases of SRCS of the bone and soft tissue diagnosed at People\'s Hospital, Peking University from January 2016 to March 2020 were recruited and retrospectively analyzed for pathological morphology, immunophenotype and fluorescence in situ hybridization (FISH) data. Next generation sequencing (NGS) was performed on 13 difficult cases. Results: In the study cohort, the patients ranged in age from 4-55 years, with a male predominance. The most Ewing\'s sarcomas and osteosarcomas occurred in the bone, while CIC-rearranged sarcomas, BCOR-rearranged sarcoma, synovial sarcoma, extraskeletal myxoid chondrosarcoma and FUS-NFATc2 rearranged sarcoma occurred in soft tissue. Histologically, all cases were composed predominantly of small round cells. Most cases were positive for vimentin and CD99, and showed a variable reactivity for neurogenic markers. Muscle marker and epithelial marker were negative for most cases. Combined with clinical features, histopathologic findings, immunophenotype, FISH and NGS, we diagnosed 46 Ewing sarcomas, 14 osteosarcomas, 3 CIC-rearranged sarcomas, 1 BCOR-rearranged sarcoma, 1 synovial sarcoma, 1 clear cell soft tissue sarcoma, 1 extraskeletal myxoid chondrosarcoma, 1 FUS-NFATc2 rearranged sarcoma, and 4 undifferentiated small round cell sarcomas. Conclusions: SRCS of bone and soft tissue is a group of malignant mesenchymal tumors based on morphological features. Most cases can be diagnosed with a combination of clinical characteristics, morphological features and immunohistochemical phenotype, while some cases require such further tests as FISH and NGS technologies, and NGS can be useful in diagnosing and categorizing SRCS.
目的: 探讨骨及软组织小圆细胞肉瘤的病理形态学表现、免疫表型、分子遗传学特征及不同检测技术的诊断价值。 方法: 收集北京大学人民医院2016年1月至2020年3月72例原发于骨及软组织的小圆细胞肉瘤,对其病理形态学表现、免疫组织化学表型及荧光原位杂交(FISH)检测结果进行回顾性分析,并对其中13例疑难病例行二代测序检测。 结果: 本组病例年龄分布在4~55岁,以男性为主,其中尤文肉瘤及小细胞骨肉瘤好发于骨组织,以长骨多见,BCOR重排肉瘤、CIC重排肉瘤、滑膜肉瘤及骨外黏液样软骨肉瘤好发于软组织;病理形态均以弥漫浸润的小圆细胞为主,免疫组织化学染色显示,几乎所有病例均表达波形蛋白和CD99,不同程度地表达神经源性标志物,上皮源性标志物和肌源性标志物表达率低;结合临床特点、形态学、免疫组织化学染色、FISH或二代测序检测诊断尤文肉瘤46例、骨肉瘤14例及透明细胞软组织肉瘤1例;经二代测序诊断3例CIC重排肉瘤及BCOR重排肉瘤、滑膜肉瘤、骨外黏液样软骨肉瘤和FUS-NFATc2融合肉瘤各1例;另有4例经FISH及二代测序检测未发现特异性分子改变,诊断为未分化小圆细胞肿瘤。 结论: 骨及软组织的小圆细胞肉瘤大部分病例结合临床、病理形态表现及免疫表现可以诊断,部分病例需借助FISH、二代测序等分子检测手段协助诊断,其中二代测序检测技术,可为此类肿瘤提供更为精确的分类及诊断。.