Kook Myeong-Cherl
Center for Gastric Cancer, National Cancer Center, Goyang, Korea.
Clin Endosc. 2019 Jan;52(1):15-20. doi: 10.5946/ce.2018.193. Epub 2019 Jan 25.
Undifferentiated-type carcinoma has a high incidence of lymph node metastasis. The independent risk factors for lymph node metastasis in undifferentiated-type carcinoma are invasion depth, tumor size, lymphovascular invasion, and presence of ulcer. In the cases that meet the curative resection criteria, no lymph node metastasis was observed in the Japanese studies, but some metastases were observed in Korean studies. After performing curative endoscopic submucosal dissection, the survival rate is similar to that of gastrectomy. The discrepancy between endoscopy and pathology is high in undifferentiated-type carcinoma. The tumor size in endoscopy is a significant risk factor for non-curative resection, and when the tumor size is small, the non-curative resection rate is significantly reduced. Lymphovascular invasion can be assessed in pathologic examination and D2-40 stain is helpful. The presence of ulcer should be determined by pathology, but ulcer's omission in pathology report makes the analysis difficult. Undifferentiatedtype carcinomas with differentiated-type components show higher lymph node metastasis rate than that of pure undifferentiatedtype carcinomas. The lymph node metastasis rate of signet ring cell type is lower than that of other undifferentiated-type carcinomas and is similar to differentiated-type carcinomas. The application of these additional histologic findings may improve the indication of endoscopic submucosal dissection.
未分化型癌的淋巴结转移发生率较高。未分化型癌发生淋巴结转移的独立危险因素包括浸润深度、肿瘤大小、淋巴管侵犯及溃疡的存在。在符合根治性切除标准的病例中，日本的研究未观察到淋巴结转移，但韩国的研究发现了一些转移情况。进行根治性内镜下黏膜下剥离术后，生存率与胃切除术相似。未分化型癌在内镜检查与病理检查之间的差异较大。内镜检查时肿瘤大小是非根治性切除的重要危险因素，当肿瘤较小时，非根治性切除率会显著降低。淋巴管侵犯可在病理检查中评估，D2-40染色有助于诊断。溃疡的存在应由病理确定，但病理报告中遗漏溃疡会使分析变得困难。具有分化型成分的未分化型癌的淋巴结转移率高于单纯未分化型癌。印戒细胞型的淋巴结转移率低于其他未分化型癌，与分化型癌相似。应用这些额外的组织学发现可能会改善内镜下黏膜下剥离术的适应证。
