title: Differentiation between sessile serrated adenoma/polyp and non-sessile serrated adenoma/polyp in large hyper plastic polyp: A Japanese collaborative study.
abstract: A hyperplastic polyp (HP) >10 mm is described as a large hyperplastic polyp (LHP). Previous studies have considered LHP and sessile serrated adenoma/polyp (SSA/P) as synonymous. Although HP and SSA/P have previously been morphologically distinguished, differences between LHP and SSA/P have not yet been reported. The present study aimed to define the differences between SSA/P and non-SSA/P in LHP using immunohistochemistry for Ki67. Colorectal serrated lesions (>10 mm) that were completely resected by endoscope and derived from 11 institutions in Japan [Dokkyo Medical University School of Medicine (Mibu), Takahiro Fujii Clinic (Tokyo), Sano Hospital (Kobe), Oda GI Clinic, Hattori GI Endoscopy and Oncology Clinic (Kumamoto), Ohta Clinic (Nagoya), Hiroshima University (Hiroshima), Iwate Medical University (Morioka), Juntendo and Kyorin Universities (Tokyo) as well as Toyama University (Toyama)] affiliated with the Japanese Society for Cancer of the Colon and Rectum (JSCCR) between January 2003 and December 2010 were selected. The histological criteria of the Japanese Society for Cancer of the Colon and Rectum (JSCCR, project meeting; editor-in chief, Takashi Yao) were used to distinguish SSA/P and non-SSA/P from LHP. Non-SSA/P comprises both incomplete SSA/P and HP. A total of 154 samples diagnosed as SSA/P or non-SSA/P from 148 patients were used. This study comprised 107 SSA/P and 47 non-SSA/P cases, whereby lesions were located on the right side of the colon (73.2 and 26.8%, respectively). Ki67-positivity in SSA/Ps was significantly higher compared to non-SSA/Ps. A greater number of SSA/Ps in LHP were located on the right side of the colon compared to the left side. SSA/Ps occurring on the right side of the colon may be precursor lesions of colorectal carcinoma in serrated neoplasia pathways. In conclusion, LHPs and SSA/Ps limited to the right side of the colon are suggested to be clinically treated as the same type of lesions.
authors.affiliation: Departments of Surgery 1 and ; Surgical and Molecular Pathology, Dokkyo Medical University School of Medicine, Mibu;
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Shida
authors.affiliation: Surgical and Molecular Pathology, Dokkyo Medical University School of Medicine, Mibu;
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Ichikawa
authors.affiliation: Surgical and Molecular Pathology, Dokkyo Medical University School of Medicine, Mibu;
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujimori
authors.affiliation: Surgical and Molecular Pathology, Dokkyo Medical University School of Medicine, Mibu;
authors.forename: Yukari
authors.initials: Y
authors.lastname: Fujimori
authors.affiliation: Surgical and Molecular Pathology, Dokkyo Medical University School of Medicine, Mibu;
authors.forename: Shigeki
authors.initials: S
authors.lastname: Tomita
authors.affiliation: Takahiro Fujii Clinic, Tokyo;
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Endoscopy Division, Gastrointestinal Center, Sano Hospital, Kobe;
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sano
authors.affiliation: Oda GI Clinic;
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Hattori GI Endoscopy and Oncology Clinic, Kumamoto;
authors.forename: Hideyo
authors.initials: H
authors.lastname: Goto
authors.affiliation: Ohta Clinic, Tokyo;
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ohta
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima;
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Division of Molecular Diagnostic Pathology, Department of Pathology, School of Medicine, Iwate Medical University, Morioka;
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sugai
authors.affiliation: Department of Human Pathology, Juntendo University School of Medicine;
authors.forename: Takashi
authors.initials: T
authors.lastname: Yao
authors.affiliation: Department of Pathology, Kyorin University School of Medicine, Tokyo;
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohkura
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan.
authors.forename: Johji
authors.initials: J
authors.lastname: Imura
authors.affiliation: Departments of Surgery 1 and.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
keywords: Ki67; large hyperplastic polyp; sessile serrated adenoma/polyp; tumor location