Chen Cuimin, Yin Weihua, Wang Xingen, Li Ping, Chen Yaoli, Jin Xianglan, Yang Ping, Wu Huanwen
Department of Pathology, Shenzhen Hospital of Peking University, Shenzhen, China.
Department of Pathology, Peking Union Medical College Hospital, Peking, China.
Front Oncol. 2021 Aug 27;11:665056. doi: 10.3389/fonc.2021.665056. eCollection 2021.
Malignant gastrointestinal neuroectodermal tumor (GNET) is a rare malignant mesenchymal neoplasm that commonly arises in the small bowel, stomach or colon. Meanwhile, SMARCA4-deficient undifferentiated carcinoma is a rarely reported entity with highly aggressive behavior that may involve the ovary, lung, gastrointestinal (GI) tract, endometrium and other organs. To our knowledge, we describe for the first time, an extremely rare case of synchronous GNET and SMARCA4-deficient undifferentiated carcinoma with independent origins in the small intestine.
A 46-year-old woman presented with multiple small intestine masses and underwent surgical resection. Two distinct entities, GNET and SMARCA4-deficient undifferentiated carcinoma, were identified. GNET was composed of epithelioid and spindle cells with clear or eosinophilic cytoplasm arranged in sheets, nest, papillary, fascicular, palisade, rosette like or pseudoalveolar pattern. The neoplastic cells were positive for S-100 and SOX-10. Ewing sarcoma breakpoint region 1 gene (EWSR1) rearrangement was confirmed by fluorescence hybridization (FISH), and EWSR1-CREB1 fusion was revealed by next-generation sequencing (NGS). SMARCA4-deficient undifferentiated carcinoma was composed mainly of poorly adhesive rhabdoid cells with eosinophilic cytoplasm arranged in a diffuse pattern. Multifocal necrosis, brisk mitotic figures as well as multinucleated tumor cells were observed. The neoplastic cells diffusely expressed pancytokeratin and vimentin, and was negative for SMARCA4(BRG1). Frame shift mutation of SMARCA4 was detected by NGS.
This is the first report that GNET and SMARCA4-deficient undifferentiated carcinoma occurred simultaneously in the small intestine, with the latter showing multiple involvement of the jejunum and ileum. The potential mechanism underlying co-existence of these two rare malignancies is unknown and need further investigations and concern.
恶性胃肠道神经外胚层肿瘤（GNET）是一种罕见的恶性间叶性肿瘤，通常发生于小肠、胃或结肠。同时，SMARCA4缺陷型未分化癌是一种报道较少的实体瘤，具有高度侵袭性，可累及卵巢、肺、胃肠道（GI）、子宫内膜及其他器官。据我们所知，我们首次描述了一例极为罕见的小肠原发性同步性GNET和SMARCA4缺陷型未分化癌病例。
一名46岁女性因多发小肠肿物就诊并接受手术切除。术中发现两个不同的肿瘤实体，即GNET和SMARCA4缺陷型未分化癌。GNET由上皮样细胞和梭形细胞组成，细胞质透明或嗜酸性，呈片状、巢状、乳头状、束状、栅栏状、玫瑰花结样或假腺泡状排列。肿瘤细胞S-100和SOX-10呈阳性。荧光原位杂交（FISH）证实尤因肉瘤断点区域1基因（EWSR1）重排，二代测序（NGS）显示EWSR1-CREB1融合。SMARCA4缺陷型未分化癌主要由黏附性差的横纹肌样细胞组成，细胞质嗜酸性，呈弥漫性排列。可见多灶性坏死、活跃的有丝分裂象以及多核肿瘤细胞。肿瘤细胞弥漫性表达全细胞角蛋白和波形蛋白，SMARCA4（BRG1）呈阴性。NGS检测到SMARCA4的移码突变。
这是首例关于GNET和SMARCA4缺陷型未分化癌同时发生于小肠的报道，后者累及空肠和回肠多处。这两种罕见恶性肿瘤共存的潜在机制尚不清楚，需要进一步研究和关注。
