Lawless Margaret E, Toweill Daniel L, Jewell Kim D, Jain Dhanpat, Lamps Laura, Krasinskas Alyssa M, Swanson Paul E, Upton Melissa P, Yeh Matthew M
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Department of Pathology, Yale University School of Medicine, New Haven, CT.
Am J Clin Pathol. 2017 Apr 1;147(4):390. doi: 10.1093/ajcp/aqx015.
Juvenile polyps involving the stomach are uncommon. Massive gastric juvenile polyposis is even rarer.
We describe the clinicopathologic features of nine cases of massive gastric juvenile polyposis.
All patients had anemia; four had hypoalbuminemia. The polyps were composed predominantly of dilated crypts lined by columnar epithelium and abundant edematous stroma with mixed inflammatory infiltrates. One patient had a poorly differentiated adenocarcinoma, arising in juvenile polyp-associated intraepithelial neoplasia. A second patient had a well-differentiated intramucosal adenocarcinoma arising in a juvenile polyp with high-grade dysplasia. Three of our cases had polyposis restricted to the stomach. Six (66.6%) had loss of SMAD4 immunoreactivity, making them subject to severe bleeding and hypoproteinemia, as well as developing severe dysplasia or adenocarcinoma.
SMAD4 immunohistochemstry is a helpful ancillary diagnostic test in cases of suspected juvenile polyposis syndrome involving the stomach.
累及胃的幼年性息肉并不常见。巨大胃幼年性息肉病则更为罕见。
我们描述了9例巨大胃幼年性息肉病的临床病理特征。
所有患者均有贫血；4例有低白蛋白血症。息肉主要由柱状上皮衬覆的扩张腺管和富含水肿性间质及混合性炎性浸润组成。1例患者在幼年性息肉相关上皮内瘤变基础上发生了低分化腺癌。另1例患者在伴有高级别异型增生的幼年性息肉中发生了高分化黏膜内腺癌。我们的病例中有3例息肉病仅限于胃。6例（66.6%）患者SMAD4免疫反应性缺失，使其易发生严重出血和低蛋白血症，以及发展为严重异型增生或腺癌。
对于怀疑累及胃的幼年性息肉病综合征病例，SMAD4免疫组化是一项有用的辅助诊断检查。
