title: A case of lymphoepithelioma-like carcinoma of the colon with ulcerative colitis.
abstract: Follow-up colonoscopy of a 25-year-old Japanese man with ulcerative colitis (UC) who had undergone endoscopic mucosal resection twice for early colon cancers revealed the presence of a new 1.5-cm-diameter tumor in the sigmoid colon. It was diagnosed by preoperative biopsy as a poorly differentiated adenocarcinoma. Sigmoidectomy was performed, and the pathological findings revealed lymphoepithelioma-like carcinoma (LEC). In situ hybridization to detect Epstein-Barr virus (EBV)-encoded small RNAs showed positive signals in stromal lymphocytes, but weak signals in the tumor cells. The association between EBV and LEC was obscure in this case. Unlike typical UC-mediated colon cancers, the lesion was poorly differentiated, and negative for p53 signals immunohistochemically. These findings may hint at a novel mechanism of carcinogenesis in UC-mediated colorectal cancer.
authors.affiliation: Department of Surgery, Yokosuka Kyosai Hospital, 1-16 Yonegahama, Yokosuka, Kanagawa, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kojima
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Mogaki
authors.forename: Ryo
authors.initials: R
authors.lastname: Takagawa
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ota
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Sugita
authors.forename: Shiho
authors.initials: S
authors.lastname: Natori
authors.forename: Yohei
authors.initials: Y
authors.lastname: Hamaguchi
authors.forename: Haruki
authors.initials: H
authors.lastname: Kurosawa
authors.forename: Tadao
authors.initials: T
authors.lastname: Fukushima
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Masui
authors.forename: Shingo
authors.initials: S
authors.lastname: Fukazawa
authors.forename: Shoji
authors.initials: S
authors.lastname: Yamanaka
authors.forename: Yukio
authors.initials: Y
authors.lastname: Tsuura
authors.forename: Kaoru
authors.initials: K
authors.lastname: Nagahori
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000150:complications* / Q000473:pathology; D003093:Colitis, Ulcerative / Q000150:complications* / Q000473:pathology; D003110:Colonic Neoplasms / Q000150:complications* / Q000473:pathology; D006801:Humans; D008297:Male