摘要目的:探讨伴肠母细胞分化的胃腺癌（gastric adenocarcinoma with enteroblastic differentiation，GAED）的临床病理学特征、免疫表型、诊断与鉴别诊断。方法:收集福建省立医院2019年8月至2020年8月诊断的12例GAED，采用HE染色、免疫组织化学及HER2基因检测的方法，探讨其临床病理学特征。并以同期诊断的343例普通型胃腺癌作为对照组，比较二者之间的临床病理差异。结果:12例GAED男10例，女2例；年龄59~75岁（中位年龄66.5岁）。临床表现腹痛、黑便伴呕血。大体检查：9例为溃疡型肿物，3例为隆起型肿物，肿瘤最大径1.5~9.5 cm（中位最大径6.0 cm）。镜下观察：肿瘤细胞排列成管状、乳头状、筛状或腺样结构，细胞呈立方或柱状，胞界相对清晰，具有特征性的丰富透明或略嗜酸性胞质。免疫表型：肿瘤细胞表达SALL4（12/12）、Glypican-3（9/12）、甲胎蛋白（5/12）、CDX2（8/12）、CD10（3/12）、p53（10/12）、HER2（2/12，3+），荧光原位杂交检测显示HER2基因扩增（2/12）。与普通型胃腺癌相比，GAED具有更高脉管侵犯及肿瘤进展率（ P<0.05），而在年龄、性别、分化程度、神经侵犯、淋巴结转移、pT分期、pN分期及pM分期上差异无统计学意义（ P>0.05）。 结论:GAED属于罕见的特殊类型胃腺癌，病理学上同时具有胚胎性分化和肠型分化两种免疫表型，生物学行为上具有更高的侵袭性，在临床诊断工作中，需要与普通型胃腺癌相区别。

abstractsObjective:To investigate the clinicopathological features, immunophenotype, diagnosis and differential diagnosis of gastric adenocarcinoma with enteroblastic differentiation (GAED).Methods:Twelve cases of GAED diagnosed in Fujian Provincial Hospital from August 2019 to August 2020 were collected. HE staining, immunohistochemistry and HER2 gene amplification were evaluated. In addition, 343 cases of gastric adenocarcinoma diagnosed in the same period were used as the control group to compare the clinicopathological differences between them.Results:The 12 cases of GAED included 10 males and 2 females, aged 59-75 years (median 66.5 years). The main clinical manifestations were abdominal pain, melena with hematemesis; nine tumors were ulcerative and three were protuberant. The tumor diameter ranged from 1.5 to 9.5 cm (median 6.0 cm). Histologically, the tumor cells were arranged in tubular, papillary, cribriform, or adenoid structures. The cells were cuboidal to columnar, with relatively distinct cell boundaries and abundant clear or slightly eosinophilic cytoplasm. Immunohistochemically, tumor cells were positive for SALL4 (12/12), glypican-3 (9/12), AFP (5/12), CDX2 (8/12), CD10 (3/12), p53 mutated (10/12), HER2 (2/12, 3+), and both cases showed HER2 gene amplification by fluorescence in situ hybridization. Compared with common gastric adenocarcinoma, GAED showed higher rate of vascular invasion and tumor progression ( P<0.05), but there were no significant differences in age, sex, degree of differentiation, nerve invasion, lymph node metastasis, pT stage, pN stage and pM stage ( P>0.05). Conclusions:GAED is a rare type of gastric adenocarcinoma. Pathologically, GAED has both embryonal and intestinal phenotypes. In terms of biological behavior, it is more invasive. GAED needs to be distinguished from common gastric adenocarcinoma in clinical diagnosis.