盲腸・上行結腸のポリープ診断

Polyp of the Right Colon

　大腸ポリープとは大腸内腔へ突出した限局性の上皮性隆起一般に対する形態上の名称である，組織形がわからないときは便利な術語である．本文中ではとくに断わらないかぎり，ポリープと腺腫とほぼ同義語として用いた．

　さて盲腸上行結腸の診断という主題のポリープを担当することになったが，盲腸上行結腸のポリープといっても大腸の他部位に比べて，診断上とくに問題があると思えないし，自験例も残念ながら少いので困る．内視鏡的にも問題点があるとすればスコープが盲腸まで入るか否かのポリープ以前の問題につきてしまうが，ここで挿入の問題に立入る気もない．そこで少し角度をかえて盲腸上行結腸のポリープに取くんでみた．

　1. The clinician, who relies largely on endoscopy and barium enema, encounters the great majority (about seventy to eightly per cent) of adenomatous polyps in the rectum and lower sigmoid colon.

　The pathologist, on the contrary, insists that more than half of adenomatous polyps exist in the right half of the colon, or the greatest concentration of these lesions per unit of surface area is actually in the cecum.

　We investigated on the distance between the clinical and pathological examination. Two assumptions were possible. First, clinical examinations, especially proctosigmoidoscopy, were more effective for the lower part of the large intestine. So the polyps of the deep colon might have been left undiscovered. Second, the average age of the patients who undergo the clinical examination is lower than that of the autopsied patients. As for the first point, results by recently developed colonoscope may give some clue. Colonoscopy, however, revealed that large part of the polyps also exist in the lower sigmoid and rectum. Therefore, the only possible explanation for the clinico-pathological dissociation is the age difference at the time of both examination. That is to say the polyps grow in the right colon at the evening of life. But no proof of it was done.

　2. Some important points for the colonoscopic examination of polyps were stressed. It is often difficult to find limitted lesions such as polyp just beyond the segment where the colon flexes kneely; hepatic flexture and several parts of the sigmoid colon. It is very important for the colonoscopy to clarify the base of the polyp ; present or absence of the stalk.