成人にみられた上行結腸重複腸管の1例

Duplication of the Ascending Colon in an Adult, Report of a Case

要旨　下痢を契機に発見された64歳男性の上行結腸消化管重複症について報告した．本症例の上行結腸後壁の半球形の腫瘤は注腸像および内視鏡像からは粘膜下腫瘍であり，CT像での内部の均一性から囊胞性病変が示唆され，上行結腸部分切除を含む回盲部切除術を施行した．摘出標本の割面像で腫瘤は大きさ5.5×4×3cm，内部にゼラチン様物質を含んだ壁の厚さ3mmの囊胞性病変であった．病理組織学的に囊胞性病変の内面は結腸型粘膜で覆われており，正常の管腔と固有筋層を共有していることから消化管重複症と診断された．本症例は回盲部付近に発生した囊腫状消化管重複症で，Kottra ＆ Dottsの分類で典型的なtype Ⅰaに相当した．

　A 64-year-old man underwent examinations because of watery diarrhea of one month duration. Barium enema (Fig. 1) and colonoscopic examinations (Fig. 2) showed a submucosal tumor of the ascending colon. Abdominal CT and US revealed a cystic pattern (Fig. 3). Under the tentative diagnosis of submucosal tumor ileocecal resection and partial resection of the ascending colon were performed. Resected specimen showed a hen egg-like soft tumor measuring 5.5×4×3 cm adherent to the posterior wall of the ascending colon (Fig. 4). Macroscopic examination showed that it contained white gelatin-like material with the wall 3 mm in thickness (Fig. 5). Histological examination revealed that the luminal surface of the cyst wall was covered by normal colonic mucosa (Fig. 6) with the muscularis mucosa (Fig. 7).

　This case corresponds to the type Ⅰa colonic duplication according to the classification by Kottra and Dotts.