title: Cancer emerging from the recurrence of sessile serrated adenoma/polyp resected endoscopically 5 years ago.
abstract: Since the serrated neoplastic pathway has been regarded as an important pathway of colorectal carcinogenesis, few reports have been published on clinical cases of cancer derived from sessile serrated adenoma/polyp, especially on recurrence after resected sessile serrated adenoma/polyp. An elderly woman underwent endoscopic mucosal resection of a flat elevated lesion, 30 mm in diameter, in the ascending colon; the histopathological diagnosis at that time was a hyperplastic polyp, now known as sessile serrated adenoma/polyp. Five years later, cancer due to the malignant transformation of the sessile serrated adenoma/polyp was detected at the same site. The endoscopic diagnosis was a deep invasive carcinoma with a remnant sessile serrated adenoma/polyp component. The carcinoma was surgically removed, and the pathological diagnosis was an adenocarcinoma with sessile serrated adenoma/polyp, which invaded the muscularis propria. The surgically removed lesion did not have a B-RAF mutation in either the sessile serrated adenoma/polyp or the carcinoma; moreover, the initial endoscopically resected lesion also did not have a B-RAF mutation. Immunohistochemistry confirmed negative MLH1 protein expression in only the cancer cells. Lynch syndrome was not detected on genomic examination. The lesion was considered to be a cancer derived from sessile serrated adenoma/polyp recurrence after endoscopic resection, because both the surgically and endoscopically resected lesions were detected at the same location and had similar pathological characteristics, with a serrated structure and low-grade atypia. Furthermore, both lesions had a rare diagnosis of a sessile serrated adenoma/polyp without B-RAF mutation. This report highlights the need for the follow-up colonoscopy after endoscopic resection and rethinking our resection procedures to improve treatment.
authors.affiliation: Digestive of Gastroenterology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo akiko.chino@jfcr.or.jp.
authors.forename: A
authors.initials: A
authors.lastname: Chino
authors.affiliation: Digestive of Surgery Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Nagayama
authors.affiliation: Digestive of Gastroenterology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: H
authors.initials: H
authors.lastname: Ishikawa
authors.affiliation: Digestive of Gastroenterology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: K
authors.initials: K
authors.lastname: Morishige
authors.affiliation: Digestive of Gastroenterology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: T
authors.initials: T
authors.lastname: Kishihara
authors.affiliation: Clinical Genetic Oncology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: M
authors.initials: M
authors.lastname: Arai
authors.affiliation: Pathology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sugiura
authors.affiliation: Pathology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Motoi
authors.affiliation: Pathology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Digestive of Gastroenterology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: Y
authors.initials: Y
authors.lastname: Tamegai
authors.affiliation: Digestive of Gastroenterology Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo.
authors.forename: M
authors.initials: M
authors.lastname: Igarashi
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000032:analysis*; D000230:Adenocarcinoma / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D000236:Adenoma / Q000737:chemistry / Q000601:surgery*; D000368:Aged; D003110:Colonic Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D003111:Colonic Polyps / Q000737:chemistry / Q000473:pathology / Q000601:surgery*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D000070957:MutL Protein Homolog 1; D009364:Neoplasm Recurrence, Local / Q000737:chemistry / Q000175:diagnosis*; D009687:Nuclear Proteins / Q000032:analysis*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000070957:MutL Protein Homolog 1
keywords: B-RAF mutation; cancer derived from sessile serrated adenoma/polyp; sessile serrated adenoma/ polyp