Case Report
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World J Gastroenterol. Jul 14, 2013; 19(26): 4262-4266
Published online Jul 14, 2013. doi: 10.3748/wjg.v19.i26.4262
A white opaque substance-positive gastric hyperplastic polyp with dysplasia
Hiroya Ueyama, Kenshi Matsumoto, Akihito Nagahara, Ryosuke Gushima, Takuo Hayashi, Takashi Yao, Sumio Watanabe
Hiroya Ueyama, Kenshi Matsumoto, Akihito Nagahara, Sumio Watanabe, Department of Gastroenterology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
Ryosuke Gushima, Takuo Hayashi, Takashi Yao, Department of Human Pathology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
Author contributions: Ueyama H designed the study and collected, analyzed and interpreted the data; Matsumoto K, Nagahara A and Watanabe S wrote and revised the paper; and Gushima R, Hayashi T and Yao T contributed to this work by providing comments on the pathology.
Correspondence to: Hiroya Ueyama, MD, PhD, Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421, Japan. psyro@juntendo.ac.jp
Telephone: +81-3-38133111 Fax: +81-3-38138862
Received: March 24, 2013
Revised: April 24, 2013
Accepted: May 7, 2013
Published online: July 14, 2013
Processing time: 111 Days and 0.6 Hours
Abstract

The endoscopic findings of gastric hyperplastic polyps (HPs) with dysplasia have not been well-defined, and the clinical significance of these lesions, including their malignant potential, is unclear. In this report, we describe a case of a white opaque substance (WOS)-positive gastric HP with dysplasia. A 76-year-old woman was referred to our hospital for endoscopic resection of a gastric HP. Upper endoscopy revealed a 25-mm whitish and reddish polypoid lesion on the greater curvature in the lower third of the stomach. The whitish part was diagnosed as a WOS using conventional and magnifying endoscopy with narrow band imaging. An examination of the biopsy specimen indicated that the lesion was a typical gastric HP. However, because of its color and the presence of a WOS, we suspected that this lesion was an atypical gastric HP. Therefore, we performed a polypectomy. Histopathologically, diffuse low- to high-grade dysplasia was found on the surface of the polyp. We performed immunohistochemical staining using a monoclonal antibody specific for adipophilin as a marker of lipid droplets (LDs). LDs were detected in approximately all of the neoplastic cells, especially in the surface epithelium of the intervening apical parts and were located in the subnuclear cytoplasm of the neoplastic cells. According to endoscopic and histopathological findings, the WOS-positive epithelium indicated dysplasia of the gastrointestinal phenotype, which could absorb lipids. The presence of a WOS in a gastric HP may be considered an endoscopic finding that is predictive of the neoplastic transformation of a gastric HP. We suggest that a WOS-positive gastric HP should be resected endoscopically to investigate its neoplastic transformation.

Keywords: Gastric hyperplastic polyp with dysplasia; White opaque substance; Adipophilin; Lipid droplet; Narrow band imaging

Core tip: In this report, we present the first case of a white opaque substance (WOS)-positive gastric hyperplastic polyp (HP) with dysplasia. We performed immunohistochemical staining using a monoclonal antibody specific for adipophilin as a marker of lipid droplets. According to endoscopic and histopathological findings, the WOS-positive epithelium corresponded to the dysplasia in this lesion. The presence of a WOS in a gastric HP may be considered an endoscopic finding that is predictive of the neoplastic transformation of a gastric HP. We suggest that patients with a WOS-positive gastric HP should be treated by endoscopic resection to investigate the neoplastic transformation of the HP.