Abstract
Colorectal cancer is diagnosed histologically in many cases as well differentiated adenocarcinoma because of histological predominance. However, there are not a few histological findings of well differentiated adenocarcinoma combined with moderately or poorly differentiated adenocarcinoma or mucinous carcinoma. Thus, the significance of histomorphological heterogeneity was examined pathologically and clinically in 640 cases of well differentiated colorectal carcinoma, and the following results were obtained.
(1) The heterogeneity was observed in 32% (203 cases) of the total cases and related to tumor extent (depth, lymph node metastasis and stage), vascular invasion (lymphatic permeation, venous invasion and perineural invasion) and proliferation by local infiltration.(2) The heterogeneity was considered to be a factor having effects on prognosis (recurrence and survival rates).(3) It was demonstrated that cancer cells showing poorly or mucinous differentiation metastasize even if they are not predominant.(4) Well differentiated adenocarcinoma combined with heterogeneity should be treated separately from that without heterogeneity.
