title: Two cases of inverted hyperplastic polyps of the colon and association with adenoma.
abstract: Here we report two cases of inverted hyperplastic polyps of the colon. The first patient showed three inverted hyperplastic polyps in the ascending colon, one of which was associated with adenoma. We immunostained this adenoma-associated polyp using anti-beta-catenin antibody and found accumulation of beta-catenin in the cytoplasm of the adenomatous lesion but not in the inverted hyperplastic polyp. This suggested an adenomatous polyposis coli (APC) mutation in the adenomatous region but not in the inverted hyperplastic polyp. The inverted hyperplastic polyp in the second patient was located at the caecum and was studied using magnifying colonoscopy. The polyp appeared to be flat and elevated with a depressed pit in the centre. After spraying with methylene blue dye, the pit pattern of the lesion was observed and small asteroid pits on the polyp were found, consistent with a hyperplastic gland pattern. From these results, we diagnosed inverted hyperplastic polyp of the colon by colonoscopy.
authors.affiliation: Department of Gastroenterology, National Hakodate Hospital, Hakodate, Japan. kageaki@sapmed.ac.jp
authors.forename: Kageaki
authors.initials: K
authors.lastname: Kuribayashi
authors.forename: Toru
authors.initials: T
authors.lastname: Ishii
authors.forename: Takuzo
authors.initials: T
authors.lastname: Ishidate
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Ban
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Hirata
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hashida
authors.forename: Katsunori
authors.initials: K
authors.lastname: Saito
authors.forename: Nozomu
authors.initials: N
authors.lastname: Iwashiro
authors.forename: Masanori
authors.initials: M
authors.lastname: Ohara
authors.forename: Masanori
authors.initials: M
authors.lastname: Ishizaka
authors.forename: Manabu
authors.initials: M
authors.lastname: Azumad
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Takayama
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000473:pathology*; D003106:Colon / Q000473:pathology; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D003598:Cytoskeletal Proteins / Q000032:analysis; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D015534:Trans-Activators / Q000032:analysis; D051176:beta Catenin
chemical_list: C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D009363:Neoplasm Proteins; D015534:Trans-Activators; D051176:beta Catenin