Abstract
The early stage of colorectal cancer is divided into two morphological types ; polypoid and superficial. What percentage of advanced cancer is derived from the polypoid or superficial type is a matter of concern. We designated superficial type tumors from the both morphological and histological viewpoints. Histological designation of superficial type tumor was that there was horizontal growth of cancer in the residual mucosa.
The existence of horizontal growing mucosal cancer at the marginal area of cancer is a biomarker showing the lesion being of superficial origin. The rates of arise from superficial tumor of submucosal cancer in the residual mucosa was 29/98 (29.6%) . The cancer with invasion deeper than the muscularis propria layer usually loose cancer in the mucosa, therefore, the rates may not reflect actual incidence. The rate of submucosal cancer (29.6%) may be close to the actual rate at present.
It may be useful to focus on the horizontal growing tumor of the colorectum for understanding the advance and development of colorectal tumors.
