大腸のVillous adenomaの5症例

Five Cases of Villous Adenoma of the Large Intestine

　大腸に発生する腫瘍性ポリープ（neoplastic polyp）の1つの型であるVillous adenomaはAdenomatous polyp（本稿ではTubular adenomaと同意的に用いる）と本質的には同一のものとも考えられるが，肉眼的および組織形態学的特徴や癌化率の高いこと，さらに臨床的に脱水症状や電解質異常等をともなうことがあること等の臨床病理学的特徴より，一般にadenomatous polypと区別して考えられている．大腸のVillous adenomaは大腸癌の多い欧米ではしばしばみられ，多数例のまとまった報告がみられるが，欧米に比して大腸癌の少ない本邦ではこの型のAdenomaはきわめて少なく，報告例もほとんどない．われわれは典型的なVillous adenomaとその癌化したと考えられる例を経験したので報告し，若干の文献的考察を加える．

　Villous adenoma of the large intestine has been reported in the English literature with an incidence from 2.3％ to 27.5％, of benign neoplastic polyps, it has rarely been reported in Japan.

　Five cases of villous adenoma are reported in this paper. Age of the 5 patients, one male and four females, ranged from 57 to 72 years, the average age being 65.4 years. Site of occurrence of these villous adenomas was only in the rectum. Length of symptoms varied from four months to five years, the average being 22 months. Most frequent symptoms were mucous, watery discharges and bloody stool. Other symptoms included diarrhea, constipation, altered bowel habit and prolapsed tumor per anus. Two patients had a benign villous adenoma histologically, composed of villi and glands lined by a single layer of tall columnar mucous secreting epithelial cells. The other three patients had a villous adenoma associated with invasive carcinoma. Abdomino-perineal resection was performed in all cases. These patients have been well up to now.