INTESTINE Vol.18 No.3(7)

連載名 第22回大腸IIc研究会 最優秀演題
題名 SSA/P癌合併症例の1例
発刊年月 2014年 05月
著者 田中 義人 秋田赤十字病院消化器病センター
著者 山野 泰穂 秋田赤十字病院消化器病センター
著者 菅井 有 岩手医科大学医学部病理学講座分子診断病理学分野
著者 山本 英一郎 札幌医科大学医学部分子生物学講座
【 要旨 】 60歳代,女性.全大腸内視鏡検査で上行結腸に10mm大の隆起性病変を認めた.病変は色素拡大内視鏡観察では開II型pitを基調としており,頂部でⅤI型pitを呈する領域を認めた.SSA/Pに合併した粘膜内癌と判断し内視鏡的粘膜切除術(EMR)を施行した.病理診断はCarcinoma in sessile serrated adenoma/polyp,癌部分:中分化管状腺癌,深達度Tis(M),ly0,v0,側方断端(-),深部断端(-)であった.なお,非癌部(SSA/P)と癌部を遺伝子解析したところともにBRAF変異,CIMP陽性であったが,癌部でのみMLH1のメチル化が高値を示したことから,SSA/Pを背景に発生したMSI陽性大腸癌である可能性が示唆される症例と考えられた.
Title Case of Carcinoma in sessile serrated adenoma/polyp
Author Yoshihito Tanaka Department of Gastroenterology, Akita Red Cross Hospital
Author Hiro-o Yamano Department of Gastroenterology, Akita Red Cross Hospital
Author Tamotsu Sugai Division of Diagnostic Molecular Pathology, Department of Pathology, Iwate Medical University
Author Eiichiro Yamamoto 1st Department of Internal Medicine, Department of Molecular Biology, Sapporo Medical University
[ Summary ] We report on a case of carcinoma in sessile serrated adenoma/polyp. The patient was a woman of 60 years old. She had a protruded lesion 10 mm in size in the ascending colon. Magnifying endoscopy indicated TypeII-open pit patterns in most of the lesion. However, Type VI pit patterns were observed in the top of the lesion. From these findings, we diagnosed this lesion as carcinoma in sessile serrated adenoma/polyp. Endoscopic mucosal resection (EMR) was perfomed. Histological diagnos is was as follows : moderately differentiated adenocarcinoma (Tis) in sessile serrated adenoma/polyp, ly0, v0, HM0, VM0. We performed gene analysis of this lesion. We recognized BRAF mutation and CIMP in both sections of the carcinoma and SSA/P, but methylation of MLH1 was found only in the carcinomial section. It was thought that this lesion was an MSI-positive colon carcinoma which occurred due to SSA/P.