電解質異常を来した直腸villous tumorの1例―electrolyte depletion syndromeの本邦報告例の検討

Rectal Tumor with Severe Fluid and Electrolyte Depletion, Report of a Case and Review of 20 Cases with Electrolyte Depletion Syndrome in Japan

要旨　患者は74歳の女性で，意識障害および多量の粘液便を主訴として近医に入院し，直腸指診で巨大な直腸腫瘍を認めたため当科へ紹介された．入院時高度な脱水および高窒素血症があり，特に血清Na⁺，Cl^-は著明に低下していた．ガストログラフィンによる注腸造影では肛門縁直上よりRaに至る毛羽立ち様変化を認める腫瘤性病変があり，大腸ファイバーでは表面が白色調，微細顆粒状を呈した隆起性病変を認めた．術前電解質および脱水の補正後，腹会陰式直腸切断術を施行した．術後経過は良好で，意識障害は軽快し，粘液排泄も消失した．組織学的には，高分化型腺癌と粘液癌の合併した絨毛腺腫であった．本邦における報告は極めてまれで，本例を含め20例である．

　Fluid and electrolyte depletion is caused by the increased secretory activity of a vinllus tumor. We encountered such a case of rectal cancer with electrolyte depletion syndrome.

　A 74-year-old female patient was admitted to a hospital in January, 1988, complaining of disturbance of consciousness and severe watery mucus diarrhea. A huge tumor was found in the rectum by digital examination and she was transferred to our hospital in April, 1988. Clinical examination showed a great amount of dehydration and azothemia. Particularly, electrolyte imbalance was noted at Na⁺120, C1-77, and K⁺ 3.6 mEq/l (Fig. 1). Contrast enema by using gastrographin revealed a huge tumor with shaggy nap features on the rectum (Fig. 2). Endoscopic study showed whitish granulated surface of the tumor (Fig. 3). Miles' operation was undertaken after fluid and electrolyte replacement had been carried out. Postoperatively, evacuation of large amounts of mucus-containing fluid ceased and her consciousness became entirely clear.

　Surgical specimen showed an ulcerated type vinllus tumor with carcinoma in the rectum, 15×15 cm in size (Fig. 4). Histological investigation showed vinous adenoma with well-differentiated adenocarcinoma and mucinous carcinoma (Fig. 6).

　Villous tumor with electrolyte depletion syndrome is rare in Japan. Only 19 cases have been reported and ours is the twentieth case.