高齢発症の潰瘍性大腸炎にみられたadenomatous changeを伴う大腸癌の1例

Ulcerative Colitis Complicated with Two Colorectal Cancers and Adenomatous Change, Report of a Case

要旨　高齢者発症の全大腸炎型潰瘍性大腸炎の長期経過後にdysplasiaを伴う大腸癌の発生を認めた1例を報告する．患者は78歳男性．50歳ごろ潰瘍性大腸炎の発症を認め，慢性持続性の経過を持つ．激しい粘血下痢にて来院し，精査にて直腸および横行結腸に癌を認め，全結腸直腸切除術を施行した．切除大腸の病理学的検索の結果，直腸にⅡa＋Ⅱc様の形態を示す中分化腺癌を認め，横行結腸から上行結腸にかけて結節隆起性ないし顆粒状の高分化腺癌を認め，いずれの癌も周辺粘膜に顆粒状を呈する異型腺管の増殖を認めた．この病変はRiddellの言うvillous mucosa，adenomatous changeに相当した．

　A 78 year-old man visited our hospital in 1984 with complaints of mucobloody stool. He had a history of continuous diarrhea since his 50th year of age with an episode of severe diarrhea at 58th year of age. Barium enema (Fig. 1) and colonoscopy (Fig. 2) showed slightly elevated lesion in the rectum, 6cm in diameter, and nodular protruded lesion in the transverse colon 7 cm in diameter. Biopsy specimen revealed both lesions were adenocarcinoma, so proctocolectomy was performed. Pathological examination of the resected specimen (Fig. 3) showed that the slightly elevated lesion in the rectum consisted of moderately differentiated adenocarcinoma invading the adventitia (Fig. 5 c, d). It also showed that nodular protruded lesion in the transverse colon consisted of well differentiated adenocarcinoma invading the subserosa. (Fig. 6 a～v d). Around these cancers, granular mucosa was wide-spread. Although all the granular mucosa in the rectum showed mild or moderate dysplasia (Fig. 7 a, b), half of the granular mucosa in the ascending colon had been invaded by cancer (Fig. 8 a ～d), and the remaining half showed mild or moderate dysplasia (Fig. 7 b, c).