兄弟に発生した若年性大腸ポリポーシス（Juvenile Polyposis Coli）の1家系・2症例の報告―とくに腺腫内癌の併存例について

Two Cases of Juvenile Polyposis Coli in a Family with Special Reference to Microcarcinoma in Associated Adenomas

　若年性大腸ポリポーシス（Juvenile Polyposis Coli）はきわめて稀な疾患であり，自験例を含めて文献上65例の報告があるにすぎない．さらにこのなかで，家族発生を示したものは12家系・41例におよび，大腸腺腫症（Adenomatosis Coli）の家系に発生したとの報告もある．また腺腫の併存例が11例認められたが，現在までに本疾患に大腸癌の併存を認めたとする報告はない．

　われわれは兄弟に発生した若年性大腸ポリポーシスの1家系を経験し，さらに1例について経過観察中に腺腫内癌の併存を確認したので，若干の文献的考察を加えて報告する．

　Two patients with juvenile polyposis coli in a family are presented.

　Case 1. A 26 years old male with a symptom of anal bleeding was found to have multiple polyps throughout the colon on barium enema. On colonoscopy polyps up to 1 cm in diameter were reddish and had typical appearances of those of juvenile polyp. Polyps of the sigmoid and rectum were removed via colonoscope.

　All the 16 polyps removed had characteristic features of juvenile polyp, and a diagnosis of juvenile polyposis coli was confirmed. No congenital abnormality was detected.

　Case 2. A 33 years old male with a symptom of anal bleeding, elder brother of case 1, was also found to have multiple polyps throughout the colon on barium enema. More than 10 polyps were seen on rigid sigmoidoscopy. The polyps were reddish and up to 1 cm in diameter. About 20 polyps of the sigmoid and rectum were removed via colonoscope and the histology of the removed polyps showed characteristic features of juvenile polyp. A diagnosis of juvenile polyposis coli was confirmed. Two years later he was colonscoped and multiple polyps up to 2 cm in diameter of the sigmoid and rectum were detected. Forteen polyps were removed via colonoscope, 7 being juvenile and 7 being adenomatous histologically.

　In 2 adenomas, 2 cm in diameter, there was microfocus of adenocarcinoma confined to the mucosa. There were no mixed juvenile and adenomatous features in a polyp nor transition from juvenile to adenomatous features.

　This is the first case of familial occurrence of juvenile polyposis coli in Japan. Although there are several reports which suggest the presence of adenomatous polyp in juvenile polyposis coli, there has been no case presented which shows carcinoma arising in adenoma in juvenile polyposis coli. Considering the fact that patients' brother and cousin had died of rectal cancer at the age of 26 and 36, juvenile polyposis coli may have a propensity to developing colon cancer in contrast to the previous concept.

　The world literature was reviewed and 65 cases of juvenile polyposis coli were collected, in which eight cases were Japanese.