EMRを施行した頂部に微小陥凹を有する有茎性大腸sm高度浸潤癌の1例

Pedunculated Ⅱc Type Early Colon Cancer Treated with Endoscopic Mucosal Resection, Report of Case

要旨　患者は75歳，男性．肉眼型の概観は有茎性ポリープであったが，その頂部にNPG型の微小Ⅱc局面を有した上行結腸sm癌EMR例を報告した．病理組織学的には高分化腺癌，深達度sm₃，ly₀，v₀であった．本病変の特異な形態の形成機序として，癌の粘膜下への著明なdownward growthのみならず，組織学的類似性からcolonic muco-submucosal elongated polyp（CMSEP）と共通した発育進展過程が推察された．自験例はその特異な形態のため，その質的診断および取り扱いに苦慮した教訓的かつ貴重な症例と思われた．

　A case of a 75-year-old man with pedunculated Ⅱc type early colon cancer in the ascending colon, that looked like a submucosal tumor was reported. Extensive pathological studies revealed that a well differentiated adenocarcinoma without adenomatous components had invaded massively into the submucosal layer. Moreover, marginal elevation of this peculiar lesion was mainly composed of extremely loose and edematous connective tissues with dilatation and proliferation of lymphatics and venules that were the pathognomonic histological features of colonic muco-submucosal elongated polyp proposed by Matake. The present case supplies valuable information concerning the diagnosis and management of early invasive colorectal cancer.