胃癌を伴った家族性大腸腺腫症

Report of a Case of Familial Adenomatosis Coli Associated with Gastric Cancer

　家族性大腸腺腫症は，大腸に多数の腺腫が若年期から，びまん性に発生し，Mendelの遺伝法則にしたがって優生遺伝し，高率に癌化の認められることから注目される疾患である．一方，本疾患では，大腸以外にも随伴病変を認めることがしばしばあり，軟部腫瘍と骨腫とを伴うものは，Gardner症候群，脳腫瘍と合併するものは，Turcot症候群と呼ばれている．

　ところが最近，大腸以外の消化管，すなわち胃，十二指腸，小腸などにもポリープなどの病変を高率に合併することが指摘されるようになってきた．

　われわれは，家族性大腸ポリポージスで外骨腫を合併し，S字状結腸および直腸に癌化を認め，さらに胃癌，胃腺腫および胃カルチノイドを合併した症例を経験した．一部はすでに発表したが，ここに改めて詳細に報告する．

　症　例

　患　者：36歳　男性

　主　訴：下腹部疼痛，粘液および血液を混じた下痢

　既往歴：生来精神薄弱で，現在でも6，7歳程度の知能と考えられる．約3年前，小石を多量に食べるということで来院したことがある．しかしその性癖は自然に消滅した．

　家族歴：父の姉は30歳代から下痢を繰り返し，42歳で腸の癌のため死亡した．また，父母は血族の結婚であり，祖母およびその他にも胃癌で死亡したものがある．患者のきょうだい9人のうち，1入に大腸リンパ管拡張症，2人には少数ながらポリープが認められた(Table1)．

　現病歴：知能遅れがあるため，症状発現の時期および初期症状は明瞭ではない．最近，数カ月前から下腹痛を訴え，1日数十回排便し血液で下着を汚すのを家族に気付かれ，近くの内科医を受診し，検査のため紹介されて来院した．

　The patient, a 36-years-old man, was admitted with the chief complaints of lower abdominal pain, diarrhea and bloody stool. In his family history, his father's sister died of colon cancer when she was 42 years old.

　Roentgenographic examination of the colon showed numerous small polypoid lesions in the entire colon. Several elevated lesions were also noticed in the sigmoid colon and rectum.

　The upper GI series revealed a defect in the greater curvature of the antrum. The endoscopic examination showed Borrmann type 2 gastric cancer in the same area and a small erosion in the lesser curvature of the antrum.

　Partial gastrectomy and resection of the descending colon, sigmoid and rectum were performed. His immediate postoperative course was uneventful, but five months after the operation we detected a palpable mass in the lower abdomen and he died of cancer 11 months after operation.

　At autopsy a cancerous mass was found in the pelvis and multiple metastatic lesions were found in the lung, liver and lymph nodes.

　Resected specimen of the stomach showed a Borrmann type 2 cancer, 35 X 28 mm in size. Histologically this tumor showed well differentiated tubular adenocarcinoma in the mucosal layer and poorly differentiated medullary adenocarcinoma in the submucosal layer. In addition, Ⅱc type adenocarcinoma, 5 X 2 mm in size, an adenoma 3 mm in diameter and a tiny carcinoid lesion were found in the posterior wall of the antrum.

　Histological study of colon revealed well differentiated adenocarcinoma in the rectum and sigmoid colon and two carcinomas in adenomas were also found in the descending colon. Totally 903 adenomas was found. Only 10 cases, including our case of familial adenomatosis coli associated with gastric cancer, have been reported up to now.