[Controversy on therapeutic modality to early colorectal carcinomas from the viewpoint of histopathological features]

We have investigated prognostic factors of early colorectal carcinoma mainly based on pathological aspects. We have experienced 175 lesions of early colorectal carcinomas, in which 116 lesions were obtained by operation and 59 lesions were endoscopically resected. Histologically, well differentiated adenocarcinoma was subclassified into two types, pure type and combined type. We expressed extent of submucosal invasion by sm depth and sm width. We represented specific pathological features in the invasive margin as single cell infiltration (SCI) and mucinous component (MUC), which were indicating biological invasiveness of submucosal invasive carcinomas. As a result of this research, we concluded that minimal submucosal invasion of early colorectal carcinoma should be defined as carcinoma having sm depth less than 1 mm and sm width less than 5 mm, on the contrary, sm massive invasion as sm depth above 1 mm or sm width above 5 mm. We guessed that SCI was good parameter of lymphatic invasion because of their correlation to other adverse prognostic factors. We make a policy that subsequent intestinal resection should be performed to early colorectal carcinomas, which having SCI or MUC concomitant with the degree of submucosal invasion more than our standard despite of absence of vascular permeation.