⑨クローン病様病変を合併した直腸癌の1例

Report of One Case of Carcinoma of the Rectum Associated with Crohn's Disease Like Lesion

　近年クローン病に対する関心が高まるとともにクローン病と腸癌との合併例も散見されるようになった．わが国では，1976年日本消化器病学会クローン病検討委員会¹⁾が，クローン病診断基準案（以後「診断基準案」と略記す）を示して以来，これにもとづいて診断されている傾向がある．

　今回，われわれは直腸癌に，上記「診断基準案」によれば，クローン病確診病変を合併した症例を経験した．しかしながら本病変は，臨床的にも病理学的にも，クローン病とはいわない方が妥当であろうという結論に達した．この点から，クローン病の特徴であるかのようにいわれる，全層性炎症・肉芽腫・裂溝などの成り立ちについて，これらが非特異的な所見にすぎないという点で，きわめて示唆に富む症例と考えられたので報告する．

　The patient was a 52-year-old man with a chief complaint of anal bleeding and dyschezia from three months before. At intrarectal digital examination, totally circumscribed protruding tumor was palpable at about five cm distance from the anal ring and index finger could not pass through. The presence of anal fistula was noted. Roentgenographic examination by use of enema revealed high degree of obstruction for a distance of 5 to 10 cm from the anus. Endoscopically, the tumor was easily bled. By biopsy, it was confirmed to be adenocarcinoma papillotubulare.

　Examination of resected specimen showed a protruding tumor of 4.5×3.5×0.8 cm in size situated at a distance of five cm from the anus. Within the region 5 cm oral to 0.5 cm anal from the tumor, foldings showed irregular elevations, giving an impression of submucosal scirrhous infiltration of the carcinoma. Histologically, the tumor was shown to be adenocarcinoma papillotubulare with depth of pm. Although elevated foldings chiefly situated in the oral side of the tumor exhibited all the characteristic features of Crohn's disease such as inflammatory changes extending throughout the entire thickness of colonic wall especially submucosal abscess, the presence of a number of non-caseous sarcoid-like granuloma and also the presence of fissures in small numbers, this lesion should be interpreted as follows: namely, in carcinoma of the rectum intralesional fissuring occurs at first, which provides causes for development of extensive inflammatory processes and formation of abscesses below submucosal layers of the oral side of the tumor with inflammation extending entire thickness of colonic wall. As a nonspecific response to these processes, a number of granuloma are produced. Therefore, this case is considered to give suggestions on nonspecific establishment of inflammation of entire thickness, granuloma and fissures.