Published in:
01-10-2021 | Helicobacter Pylori | Original Article
Sporadic foveolar-type gastric adenoma with a raspberry-like appearance in Helicobacter pylori–naïve patients
Authors:
Kotaro Shibagaki, Tsuyoshi Mishiro, Chika Fukuyama, Yusuke Takahashi, Ayako Itawaki, Saya Nonomura, Noritsugu Yamashita, Satoshi Kotani, Hironobu Mikami, Daisuke Izumi, Kousaku Kawashima, Norihisa Ishimura, Mamiko Nagase, Asuka Araki, Noriyoshi Ishikawa, Riruke Maruyama, Ryoji Kushima, Shunji Ishihara
Published in:
Virchows Archiv
|
Issue 4/2021
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Abstract
Sporadic foveolar-type gastric adenoma (FGA) has been described as an extremely rare polyp that is whitish and flatly elevated. However, we recently found that sporadic FGA with a raspberry-like appearance (FGA-RA) is not rare in Helicobacter pylori (H. pylori)–naïve gastric mucosa. We endoscopically or surgically treated 647 patients with gastric epithelial neoplasms in the last 5 years, with 7.7% (50/647) being H. pylori–naïve. Among these, 43 FGA-RAs were diagnosed based on histologic and endoscopic features in 34 patients, who were all enrolled in this retrospective study. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We subsequently analyzed their endoscopic and microscopic features and patient characteristics. The patients were 22 males and 12 females aged 57±23 years (mean±2SD). WLE showed raspberry-like small polyps mimicking gastric hyperplastic polyps in the oxyntic gastric compartment (body/fundus). Multiple growths were confirmed in 20.6% (7/34) of the patients. NBIME revealed irregularly shaped papillary/gyrus-like microstructures with abnormal capillaries. Histologically, all lesions were intraepithelial neoplasms, and most of lesions (62.8%, 27/43) exhibited low-grade dysplasia. Immunohistochemically, neoplastic cells featured strong and diffuse MUC5AC expression, negative or very low MUC6 expression, and negative MUC2/CD10 expression. They also showed Ki-67 hyperexpression with a mean labeling index of 59.4±48.7%. The coexistence of fundic gland polyps in the background mucosa was significantly higher in multiple FGA-RA cases than in solitary cases (100% vs. 55.5%, P< 0.05). FGA-RA is a newly suggested histologic variant of sporadic FGA whose occurrence is not rare in daily endoscopic practice.