特異な“蛇の抜けがら状”注腸像を示した大腸未分化癌の1例

Undifferentiated Carcinoma of the Colon Showing an Unusual Roentgenogram by Barium Enema as “the Cast Skin of a Snake”, Report of a Case

要旨　患者は66歳，男性で，腹満感，便秘を主訴として入院した．注腸造影にて直腸上部から下行結腸上部に至るまで管腔狭小化，変形があり，比較的柔らかい壁，外圧性の偏位・固定，直腸上部に原発巣を疑わせる陰影欠損，潰瘍などが認められた．二重造影では粘膜面は浮腫状，平滑で，襞は縦走状，網状，多発小隆起をなし，壁は棘状，鋸歯状を呈した．全体として“蛇の抜けがら状”所見であった．内視鏡所見は直腸に潰瘍性病変，その上方に粘膜下浸潤を思わせる襞の多発小隆起，縦走であった．開腹所見は，正常外観構造を保持した巨大なピンクのソーセージ状のS状結腸を認めた．組織所見では無構造充実性増殖で異型性の強いPAS Alcian-blue染色陰性の未分化癌であった．

　A 66 year-old man was admitted to our hospital with chief complaints of abdominal fullness after meals and constipation. A barium enema revealed deformities and a narrowing between the discending colon and the rectum with rather soft walls, displaced by extrinsic pressure and fixation. A filling defect with an ulcer crater in the rectum was considered as the primary seat. The double contrast picture of the sigmoid showed abnormal mucosal folds which were edematous, though smooth. Longitudinal, reticulate and multiple coarse nodular folds like pseudopolyposis were present. The wall of the loop was seen as a serrated or spicular shape or tiny filling defects. These findings of roentgenogram by a barium enema were expressed as “the cast skin of a snake”. The endoscopic picture demonstrated a crater in the rectum and submucosal infiltration of the tumor cells in the sigmoid. There were no erosions and ulcers through the sigmoid except for the ulcer of the rectum.

　Exploratory laparotomy disclosed a tortuous, enormous, pink and sausage-like sigmoid colon. Macroscopic appearance of it kept normal construction with taenia and a large tumor existed in a mesenteric region. Tumor cells seemed to have invaded mainly the submucosal space of the sigmoid from the primary lesion of the rectum, associated with extrinsic growth. Histological examination revealed tumor cells that varied in size and shape with severe atypism. A solid and amorphous growth pattern was seen. There were no positive substances in PAS and Alcian-blue stained specimens. It was concluded that this tumor was an undifferentiated carcinoma originated from the colon.