Abstract
We have been investigating histophathological feature under the muscularis mucosae and degree of invasion of submucosal invasive cancer for the purpose of search for the risk factors of lymph node metastasis and recurrence. We subclassified we
ll differentiated adenocarcinoma histologically into two types i. e. simple and mixed type. We represented specific pathological features in the deepest portion of cancer as single cell infiltration (SCI) and mucinous component (MUC) . As for the degree of invasion, we classified it into three grades according to“sm depth”and“sm width”which indicated vertical and horizontal extention of carcinoma in the interstitium.
Ninty-six cases of submucosal invasive cancer (11 cases with lymph node metastasis or recurrence) were investigated clinicopathologically. Eight of 11 cases lymph node metastasis or recurrence were located in the rectum, 9 of 11 cases showed Is-type appearance. Concerning risk factor, lymphatic invasion, venous invasion and SCI had significant relation to metastasis and recurrence. All of 11 cases showed massive submucosal invasion classed as Grade-3 (sm depth＞1000µm and sm width＞4 mm) .
In order to evaluated these pathological risk factors enough, we have been performing endoscopic treatment for all lesion except one which cannot be resected curatively. According to the result of complete pathological examination, we decide the way to treat. We consider the absolute indication of subsequent intestinal resection after endoscopic resection is as follows, (1)SCI (+) , (2)lymphatic invasion (+) , (3)venous invasion (+) , (4)Graded-3, (5)lesion contains component of moderately or poorly defferentiated adenocarcinoma.
