Chen Zong-Ming, Scudiere Jennifer R, Abraham Susan C, Montgomery Elizabeth
Department of Pathology, Johns Hopkins University, Baltimore, MD 21231-2410, USA.
Am J Surg Pathol. 2009 Feb;33(2):186-93. doi: 10.1097/PAS.0b013e31817d7ff4.
Pyloric gland adenoma (PGA) is a rare neoplasm demonstrating gastric epithelial differentiation. In this series, we studied 41 PGAs from 36 patients. We compared them to 28 gastric foveolar type gastric adenomas (GTAs) from 25 patients. PGAs occurred in an older population with a mean age of 73 compared with 48 in GTAs (P<0.001). There was a significant female predominance, particularly for gastric PGAs. Morphologically, PGAs were characterized by closely packed pyloric gland-type tubules with a monolayer of cuboidal to low columnar epithelial cells containing round nuclei and pale to eosinophilic cytoplasm with a ground glass appearance. The cells lacked an apical mucin cap, a feature distinct from GTAs. An immunohistochemical panel of mucin core peptides (MUCs) and CDX2 was performed on a subset of the lesions. All PGAs expressed MUC6 with coexpression of MUC5AC, whereas GTAs expressed predominantly MUC5AC without MUC6. Both lesions lacked CDX2 and MUC2 except in areas of intestinal metaplasia (IM) found in some PGAs. Histologic features consistent with conventional dysplasia were found in 26 (63.4%) PGAs. Using a 2-tier grading system, 5 (12.2%) cases demonstrated low-grade dysplasia whereas 21 (51.2%) cases showed high-grade dysplasia including 5 (12.2%) cases with an associated intramucosal or more deeply invasive adenocarcinoma. This was significantly different from GTAs; all cases showed only low-grade dysplasia (P<0.001). In addition, 60% of gastric PGAs were associated with IM in the surrounding mucosa and 40% of lesions arose in a background of autoimmune gastritis, whereas these 2 conditions were only associated with 1 case (3%) of GTA. In summary, PGA is a distinct entity. Despite its bland histologic appearance, it is much more likely to be accompanied by background IM and autoimmune gastritis and can evolve into invasive adenocarcinoma displaying pyloric gland differentiation.
幽门腺腺瘤（PGA）是一种罕见的具有胃上皮分化的肿瘤。在本系列研究中，我们对36例患者的41个PGA进行了研究。我们将它们与25例患者的28个胃小凹型胃腺瘤（GTA）进行了比较。PGA发生于年龄较大的人群，平均年龄为73岁，而GTA的平均年龄为48岁（P<0.001）。女性明显居多，尤其是胃PGA。形态学上，PGA的特征是紧密排列的幽门腺型小管，由单层立方形至低柱状上皮细胞组成，细胞核圆形，细胞质淡染至嗜酸性，呈毛玻璃样外观。细胞缺乏顶端黏液帽，这一特征与GTA不同。对部分病变进行了黏蛋白核心肽（MUCs）和CDX2的免疫组织化学检测。所有PGA均表达MUC6并伴有MUC5AC共表达，而GTA主要表达MUC5AC且无MUC6表达。除了在一些PGA中发现的肠化生（IM）区域外，两种病变均缺乏CDX2和MUC2。26个（63.4%）PGA具有与传统发育异常一致的组织学特征。采用两级分级系统，5个（12.2%）病例表现为低级别发育异常，而21个（51.2%）病例表现为高级别发育异常，其中5个（12.2%）病例伴有黏膜内或更深层浸润性腺癌。这与GTA有显著差异；所有GTA病例仅表现为低级别发育异常（P<0.001）。此外，60%的胃PGA与周围黏膜的IM相关，40%的病变发生于自身免疫性胃炎背景下，而这两种情况仅与1例（3%）GTA相关。总之，PGA是一种独特的实体。尽管其组织学外观平淡，但更有可能伴有背景IM和自身免疫性胃炎，并且可演变为显示幽门腺分化的浸润性腺癌。
