下部直腸にびまん型浸潤を来した胃原発転移性大腸癌の1例

Circumferential Involvement of the Distal Rectum Secondary to Carcinoma of the Stomach, Report of a Case

要旨　症例は，39歳，女性．便秘・下痢・体重減少を主訴とし，近医を受診した．注腸X線にて，下部直腸（Ra～Rb portion）に全周性の狭窄および不整な結節状粘膜を認め，さらに上行結腸から脾彎曲部にかけては，多発する壁の伸展不良およびひだの収束像を認めた．上部消化管の検索にて，胃体上部から前庭部の全周を占める進行胃癌（4型，低分化腺癌）を認めたことから，胃原発の転移性大腸癌と考えられた．腹膜播種に伴う転移性大腸癌の罹患部位は，一般に腹膜反転部より口側であるが，自験例のごとくまれに肛側の下部直腸に及ぶことがあり，下部直腸の病変が発見の契機となりうることを認識しておくべきと考えられた．

　A 39-year-old woman was referred to our hospital complaining of constipation, diarrhea and weight loss. Barium enema demonstrated not only diffuse narrowing with an irregular surface in the distal rectum, but also rigidity and mucosal tethering from the ascending colon to the splenic flexure suggestive of intraperitoneal seeding. Upper GI series revealed a scirrhous carcinoma of the stomach. Histopathologically, this was shown to be a poorly differentiated adenocarcinoma. Intraperitoneal seeding most commonly occurs in rectovesical or rectouterine space, but it should be recognized that intraperitoneal seeding may spread to the distal rectum beyond the peritoneal reflexion resulting in circumferential involvement.