Inverted hyperplastic polyp diagnosed accurately by magnifying colonoscopy

Abstract

Colonic inverted hyperplastic polyps, which are characterized by epithelial misplacement or inversion of the epithelium into the submucosa, are an unusual and variant form of exophytic hyperplastic (metaplastic) polyp. 1 Sobin LH Inverted hyperplastic polyps of the colon. Am J Surg Pathol. 1985; 9: 265-272 Crossref PubMed Scopus (49) Google Scholar Because inverted hyperplastic polyps have a distinctive pitted surface macroscopically, similar to that of invasive carcinoma or depressed type adenoma, 2 Shepherd NA Inverted hyperplastic polyposis of the colon. J Clin Pathol. 1993; 46: 56-60 Crossref PubMed Scopus (30) Google Scholar they are difficult to diagnose endoscopically. It has been claimed that by examining the surface structure of the colorectal mucosa using a magnifying colonoscope, a precise and instantaneous diagnosis of colorectal lesions can be made. 3 Kudo S Tamura S Nakajima T Yamano H Kusaka H Watanabe H Diagnosis of colorectal tumorous lesions by magnifying endoscopy. Gastrointest Endosc. 1996; 44: 8-14 Abstract Full Text Full Text PDF PubMed Scopus (876) Google Scholar , 4 Mizuno M Matsumoto T Iida M Shimizu M Magnifying colonoscopic features in non-neoplastic polyps of the colorectum. Gastrointest Endosc. 1997; 46: 537-541 Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar However, there have been no reports of the efficacy of colonoscopy, including magnified observation, for the diagnosis of inverted hyperplastic polyps. We report the use of magnifying colonoscopy for accurate diagnosis of an inverted hyperplastic polyp in the ascending colon.