Definition: Gastrointestianl clear cell sarcoma/ malignant gastrointestinal neuroectodermal tumor is a sarcoma involving the GI tract with neuroectodermal differentiation and gene fusion translocations involving EWSR1, usually EWSR1-ATF1 or EWSR1-CREB1. | 定义：胃肠道透明细胞肉瘤/胃肠道恶性神经外胚层肿瘤是一种累及胃肠道的肉瘤，具有神经外胚层分化和EWSR1基因易位，通常为EWSR1-ATF1或EWSR1-CREB1基因融合。 |
ICD-O coding: 9044/3 Clear cell sarcoma NOS | ICD-0编码：9044/3非特指型透明细胞肉瘤 |
ICD-11 coding: XH77N6 Clear cell sarcoma | ICD-11编码：XH77N6透明细胞肉瘤 |
Related terminology: None | 相关术语：无 |
Subtype(s): None | 亚型：无 |
Localization: The most common locations are the small intestine, stomach, and colon. | 部位：最常见的部位是小肠、胃和结肠。 |
Clinical features: Gastrointestianl clear cell sarcoma-like tumor has a predilection for arising in young adults but can also occur in old age. It is a aggressive tumor that often metastasizes to regional lymph nodes and liver, and metastases are often detected at presentation. | 临床特点：胃肠道透明细胞肉瘤样肿瘤易发生于年轻人，但也可发生于老年人。它是一种侵袭性肿瘤，常转移到局部淋巴结和肝脏，转移常在出现时被发现。 |
Etiology: Unknown | 病因：不明 |
Epidemiology: Tumours reported as gastrointestinal neuroectodermal tumor have a median patient age of 33 years (rang: 10-81 years) and an even sex distribution, whereas tumours reported as GI tract clear cell sarcoma have a higher median age (57 years; range:35-85 years) and 85% of the cases occur in males. | 流行病学：以胃肠道神经外胚层肿瘤命名的报道中，患者中位年龄为33岁（范围：10～81岁），无性别差异，以胃肠道透明细胞肉瘤命名的报道中，患者中位年龄数较高（57岁；范围：35～85岁），85%的病例发生于男性。 |
Pathogenesis: Most cases contain EWSR1 gene aberrations, with ATF1 or CREB1 as the partner. | 发病机制：大多数病例有EWSR1基因异常，伙伴基因为ATF1或CREB1。 |
Macroscopic appearance: The tumours are 2-15 cm in size and variably form endophytic polypoid masses or mural lesions, often with ulceration resembling common carcinomas. The tumours are solid and often lobulated and tan-white on sectioning. | 大体表现：肿瘤大小为2～15厘米，内生息肉样肿块或胃肠壁发生病变，常伴有溃疡，与常见的癌相似。肿瘤呈实性，常呈分叶状，切片呈棕褐色。 |
Histopathology: Most cases show round cell histology with uniform cells in vague nested or pseudopapillary patterns, but spindle cell histology is seen occasionally. The cells contain large round nuclei with vesicular chromatin and usually inconspicuous but occasionally prominent nucleoli. The cytoplasm is usually pale eosinophilic and shows clearing only in a minority of cases. Half of the cases contain osteoclastic giant cells. Mitotic activity is variable.Immunohistochemically, positivity for S100 and SOX10 is typical, whereas markers that are more melanocyte-specific (HMB45, Melan-A, and MITF) are negative. CD56 and synaptophysin positivity is a characteristic feature, and the neuroblastoma marker NB84 can also be expressed. Unlike gastrointestinal stromal tumor, these tumours are negative for KIT and DOG1. They are also negative for chromogranin, CD34, desmin, keratins, and SMA. It is debated whether GI tract clear cell sarcoma and malignant gastrointestinal neuroectodermal tumor should be considered different tumours or the same tumour with different degrees of differentiation.Many authorities prefer the term 'clear cell sarcoma' when there is expression of Melan-A, HMB45, or MITF and the term 'malignant gastrointestinal neuroectodermal tumor' when these markers are absent. The primary differential diagnosis is with metastatic melanoma. The absence of a clinical history of melanoma is supportive, and the demonstration of EWSR1 gene rearrangement is definitive. The distinction from other sarcoma harbouing EWSR1 gene rearrangements is based on the combination of morphology and immunohistochemistry. | 组织病理学：大多数病例表现为圆形细胞组织学形态，细胞一致，呈模糊的巢状或假乳头状，但偶尔可见梭形细胞组织学形态。细胞核大，圆形，染色质空泡状，核仁通常不明显，但偶尔明显。细胞质通常淡染嗜酸性，只有少数病例显示为胞质透亮。半数病例含有破骨样巨细胞。核分裂象多少不等。免疫表型上，S100和SOX10是典型阳性的，而黑素细胞特异性更强的标记物（HMB45、Melan-A和MITF）阴性表达。CD56和突触素（syn）阳性是其典型的特征，也可表达神经母细胞瘤标志物NB84。与胃肠道间质瘤不同，这些肿瘤不表达KIT和DOG1。它们也不表达CgA、CD34、desmin、角蛋白和SMA。 胃肠道透明细胞肉瘤和胃肠道恶性神经外胚层肿瘤是否应被视为不同的肿瘤或同一个具有不同分化程度的肿瘤尚存在争议。当表达Melan-A、HMB45或MITF时，许多权威机构倾向于使用“透明细胞肉瘤”一词，当这些标记物阴性表达时，则使用“恶性胃肠道神经外胚层肿瘤”一词。 主要的鉴别诊断是转移性黑色素瘤。没有黑色素瘤的临床病史是支持胃肠道透明细胞肉瘤的，证实具有EWSR1基因重排则确定其诊断。根据形态学和免疫表型有助于与其他具有EWSR1基因重排的肉瘤进行鉴别。 |
|
Cytology: Not clinically relevant | 细胞学：无临床相关的 |
Diagnostic molecular pathology: Most cases contain EWSR1 gene aberrations. Most have an EWSR1-ATF1 fusion similar to that of peripheral clear cell sarcoma, and a minority of cases contain an EWSR1-CREB1 fusion. | 分子诊断病理学：大多数病例有EWSR1基因异常。大多数病例具有与外周透明细胞肉瘤相似的EWSR1-ATF1基因融合，少数病例含有EWSR1-CREB1基因融合。 |
Essential and desirable diagnostic criteria: Essential：positivity for S100 and SOX10; EWSR1 fusion gene. | 必要的和有帮助的诊断标准： 必要的: S100和SOX10阳性；EWSR1基因融合。 |
Staging (TNM): Not clinically relevant | 分期（TNM）：无临床相关的 |
Prognosis and prediction: Not clinically relevant | 预后和预测：无临床相关的 |
参考文献 [1] WHO Classification of Tumours of the Digestive System,5th Edition. 2019. |
