Liu Zi-Lin, Zhou Bin, Zhao Yi-Jun, Yu Miao-Qing, Liang Jie, Li Yong
Zhuhai Interventional Medical Center, Zhuhai Hospital Affiliated with Jinan University, Jinan University (Zhuhai People's Hospital), Zhuhai, China.
Department of Pathology, Zhuhai Hospital Affiliated with Jinan University, Jinan University (Zhuhai People's Hospital), Zhuhai, China.
J Gastrointest Oncol. 2022 Jun;13(3):1489-1498. doi: 10.21037/jgo-22-387.
Malignant gastrointestinal neuroectodermal tumor (GNET) is extremely rare in soft tissue sarcoma and occurs mainly in the small intestine of young adults, without sex predilection. Local recurrence and metastasis are common in GNET, resulting in a poor prognosis. GNETs are histologically and immunohistochemically similar to many sarcomas, especially clear cell sarcoma (CCS), making their identification difficult. The majority of GNET cases have gene rearrangements, which can be characterized at the genetic level and provide important clues for diagnosis of GNETs. However, very few studies have been conducted on GNET cases without common gene fusion in soft tissue tumors.
A 48-year-old woman was admitted due to melena and worsening fatigue and dizziness. An abdominal computed tomography scan revealed a mass arising from the stomach with hepatic metastases. Based on the evidence of histology and immunohistochemistry, the final diagnosis was GNET. Then we performed a gene analysis of the tumor using fluorescence hybridization and next-generation sequencing, including whole-exome sequencing and multiplex polymerase chain reaction. We did not detect any common gene fusion in the soft tissue tumors, such as EWSR1. The results of the whole-exome sequencing revealed 11 genes involved in the occurrence and development of soft tissue sarcomas. Six months after surgery, the patient's abdominal computed tomography (CT) showed new metastases in the liver. Hence, we used targeted therapy and immunotherapy to treat her and liver metastases were reduced.
Genetic diagnosis is one of the important evidences for the diagnosis of GNET. However, the cases of GNET with negative EWSR1 expression are rare, which makes clinical diagnosis difficult. Our findings may extend genetic understandings of GNET and provide more help for clinical diagnosis of GNET.
恶性胃肠道神经外胚层肿瘤（GNET）在软组织肉瘤中极为罕见，主要发生于年轻成年人的小肠，无性别倾向。GNET局部复发和转移常见，预后较差。GNET在组织学和免疫组化方面与许多肉瘤相似，尤其是透明细胞肉瘤（CCS），这使得其鉴别诊断困难。大多数GNET病例存在基因重排，可在基因水平进行特征分析，为GNET的诊断提供重要线索。然而，针对软组织肿瘤中无常见基因融合的GNET病例的研究极少。
一名48岁女性因黑便、疲劳和头晕加重入院。腹部计算机断层扫描显示胃内有一肿物并伴有肝转移。根据组织学和免疫组化证据，最终诊断为GNET。然后我们使用荧光原位杂交和二代测序对肿瘤进行基因分析，包括全外显子测序和多重聚合酶链反应。我们未在软组织肿瘤中检测到任何常见基因融合，如EWSR1。全外显子测序结果显示有11个基因参与软组织肉瘤的发生发展。术后6个月，患者腹部计算机断层扫描（CT）显示肝脏出现新的转移灶。因此，我们对她采用靶向治疗和免疫治疗，肝转移灶有所减少。
基因诊断是GNET诊断的重要依据之一。然而，EWSR1表达阴性的GNET病例罕见，这使得临床诊断困难。我们的发现可能会扩展对GNET的基因认识，并为GNET的临床诊断提供更多帮助。
