2014 Volume 64 Issue 2-4 Pages 158-169
Recently, laterally spreading tumor (LST) of early colorectal carcinoma has been treated by endoscopic submucosal dissection (ESD) more frequently. Many cases of early colorectal carcinomas are diagnosed as well differentiated adenocarcinomas, but histological and/or immunohistorogical heterogeneity is often seen in LSTs. In this study, we analyzed morphological characteristics of 61 lesions of LST-type early colorectal carcinoma by using histolosical and immunohistochemical procedures. Presence of high grade atypia components was significantly correlated with depth of submucosal invasion (P=0.0102), and these were predominantly located to the invasive front (deep part) of the submucosal carcinoma. Allred scores of p53 and Ki-67 labeling indices were increased in the component of high grade atypia regardless of depth of invasion. Expressions of CDX2 and CD10 were significantly upregulated in a depth-of-invasion dependent manner, and these tended to be highly expressed in the high grade atypias. In conclusion, the present study indicates that the majority of LST is histologically heterogeneic. The component of high grade atypia of LST upregulates cell proliferation, which may leed to increase the malignant potential of LST for invading the submucosa.
