術後5年目に発症した回盲部に限局した胃癌の結腸転移の1例―いわゆるlinitis plastica型大腸癌と炎症性腸疾患のX線所見の対比を中心に

Secondary Linitis Plastica Type Carcinoma of the Ileocecal Region Metastatic from the Advanced Gastric Carcinoma, Report of a Case

要旨　5年前に進行胃癌で胃全摘術を施行された49歳の女性が右下腹部腫瘤を主訴に来院．注腸二重造影を行ったところ，回盲部を中心に粗大穎粒状粘膜像，腸管腔の狭小化，鋸歯状陰影を認めたが，大腸ファイバースコープ，上腸間膜動脈造影，腹部CTスキャンなどの画像診断では明らかな悪性所見が得られず，また腫瘍マーカーも正常範囲内であり，術前には炎症性腸疾患（IBD）と結腸癌との鑑別はできなかった．開腹術を行ったところ，Schnitzler転移を認めたが，回盲部切除により結腸癌は切除できた．組織学的には，著明な線維の増生を伴う低分化型腺癌が粘膜下層から漿膜にかけて認められたが，軽度の粘膜固有層内への浸潤はあるものの粘膜表面への癌の露出はみられなかった．linitis plastica型結腸癌とIBDとの鑑別には，注腸X線造影上，①不規則な粗大顆粒状粘膜像，②腸管壁の著明な伸展不良，③陰影欠損を伴う腸管の変形などの所見が有用であると考えられた．

　A 49-year-old woman was admitted to our hospital on June 15, 1985, because of right lower abdominal mass. She had a past history of total gastrectomy with splenectomy for the advanced gastric carcinoma 5 years prior to the admission.

　Barium enema radiographs showed marginal serration of the bowel wall, narrowing of the bowel canal, and coarse granular pattern of the mucosal surface. However, no signs suggestive of malignancy were found either by colonofiberscopy, abdominal CT-scan or selective angiogram of the SMA. Thus, we could not determine the lesion as carcinomatous or inflammatory preoperatively.

　At operation, although disseminated nodules of poorly differentiated adenocarcinoma were found in the Douglas' pouch, the ileocecal resection was successfully performed.

　Histologically, there was diffuse scirrhous infiltration of poorly differentiated adenocarcinoma involving the entire layer of the intestinal wall except for the mucosal surface, indicating the metastasis of the gastric carcinoma resected about 5 years previously.

　Linitis plastica type colonic carcinoma resembles to inflammatory bowel disease (IBD) in the findings of barium enema radiography, but we can differentiate them based on three x-ray signs.

　1) Irregular-shaped coarse granular pattern of the mucosal surface.

　2) Markedly decreased distensibility of the bowel wall with marginal serration and spicular formation.

　3) Irregular deformity of the bowel canal with filling defect.