Kojima Yasuyuki, Mogaki Masatoshi, Takagawa Ryo, Ota Ikuko, Sugita Mitsutaka, Natori Shiho, Hamaguchi Yohei, Kurosawa Haruki, Fukushima Tadao, Masui Hidenobu, Fukazawa Shingo, Yamanaka Shoji, Tsuura Yukio, Nagahori Kaoru
Department of Surgery, Yokosuka Kyosai Hospital, 1-16 Yonegahama, Yokosuka, Kanagawa, Japan.
J Gastroenterol. 2007 Feb;42(2):181-5. doi: 10.1007/s00535-006-1981-0. Epub 2007 Mar 12.
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.
一名25岁患有溃疡性结肠炎（UC）的日本男性曾因早期结肠癌接受过两次内镜黏膜切除术，其后续结肠镜检查显示乙状结肠出现了一个新的直径1.5厘米的肿瘤。术前活检诊断为低分化腺癌。进行了乙状结肠切除术，病理结果显示为淋巴上皮瘤样癌（LEC）。检测爱泼斯坦-巴尔病毒（EBV）编码小RNA的原位杂交在基质淋巴细胞中显示出阳性信号，但在肿瘤细胞中信号较弱。在该病例中，EBV与LEC之间的关联尚不明确。与典型的UC介导的结肠癌不同，该病变分化程度低，免疫组化p53信号为阴性。这些发现可能暗示了UC介导的结直肠癌新的致癌机制。
