胃错构瘤性内翻性息肉5例临床病理学分析

Gastric hamartomatous inverted polyps:a clinicopathological analysis of five cases

目的探讨胃错构瘤性内翻性息肉(gastric hamartomatous inverted polyp,GHIP)的内镜特征、组织病理学特征、诊断及鉴别诊断。方法收集并观察广东省中医院大学城医院病理科2021年5月至2023年5月诊断的5例GHIP内镜特征及病理形态特点和免疫组织化学结果,复习相关文献进行分析。结果收集的GHIP患者中男性3例,女性2例,发病年龄49~60岁,平均年龄56岁。病变位于胃底及胃体,内镜下表现为息肉或黏膜下隆起外观。显微镜下病变主要位于黏膜下层,由分叶状或簇状增生的胃型腺上皮及增生的平滑肌包绕构成,部分区域可见模拟正常胃黏膜的分化层次的腺体成分,表现为中央不规则扩张的腺体成分为增生的小凹型上皮,而周围的腺体为胃底腺或幽门腺成分;另见部分区域腺体明显囊状扩张,排列紊乱,缺乏分化层次。增生的腺上皮成分包括小凹型上皮、胃底腺及幽门腺,并散在存在神经内分泌细胞,间质见增生的平滑肌组织。免疫组织化学结果显示病变内各种腺上皮分别表达MUC5AC、MUC6、PepsinogenⅠ、H^(+)/K^(+)ATPaseβ,未见MUC2表达,散在分布的神经内分泌细胞显示突触素阳性,结蛋白显示增生的平滑肌组织。1例归类为2型胃内翻性息肉,4例归类为3型。结论GHIP是一种罕见的胃息肉病变,具有特殊的组织学形态特点,需与内翻性增生性息肉、深在性囊性胃炎、腺肌瘤、增生性息肉、胃高分化管状腺癌等病变相鉴别,提高对其的准确认识可避免误诊或过诊的发生。

Objective To investigate the endoscopic and histopathological features,diagnosis and differential diagnosis of gastric hamartomatous inverted polyp(GHIP).Methods Five cases of GHIP were collected at the University Town Hospital of Guangdong Provincial Hospital of Chinese Medicine,Guangzhou,China,from May 2021 to May 2023.The endoscopic,pathological and immunohistochemical features of the 5 GHIP cases were analyzed.The relevant literature was reviewed.Results There were 3 males and 2 females,aged from 49 to 60 years,with a mean age of 56 years.The lesions were located in the fundus and body of the stomach,and presented as polyps or masses under endoscopy.Microscopically,the lesions were mainly in the submucosa and consisted of lobulated or clustered gastric glandular epithelium surrounded by hyperplastic smooth muscle.In some areas,there were differentiated glandular elements mimicking the normal gastric mucosa.The irregularly dilated glandular elements in the center were lined by hyperplastic foveolar epithelium,while the glands in the periphery were fundic or pyloric glands.In addition,in some areas,the glands showed cystic expansion,disordered arrangement and lack of differentiation.The hyperplastic glandular epithelium included foveolar epithelium,fundic gland and pyloric gland.There were scattered neuroendocrine cells and smooth muscle bundles in the stroma.Immunohistochemically,the tumor cells were positive for MUC5AC,MUC6,PepsinogenⅠand H^(+)/K^(+)ATPaseβ,but negative for MUC2.The scattered neuroendocrine cells were positive for synaptophysin,and the desmin stain highlighted hyperplastic smooth muscle bundles.One case was classified as type 2 gastric inverted polyp,and 4 cases were classified as type 3.Conclusions GHIP is a rare gastric polyp with unique histological features.It should be distinguished from inverted hyperplastic polyp,gastritis cystica profunda,adenomyoma,hyperplastic polyps and well-differentiated gastric tubular adenocarcinoma,etc.Improving the understanding of its pathogenesis and diagnostic features can help avoid misdiagnoses.