Most of the colorectal cancer has grown from the adenomatous polyp. Adenomatous lesions have a well-documented
relationship to colorectal cancer in previous studies. Thus, to detect the morphological changes between polyp and tumor
can allow early diagnosis of colorectal cancer and simultaneous removal of lesions. OCT (Optical coherence
tomography) has been several advantages including high resolution and non-invasive cross-sectional image in vivo. In
this study, we investigated the relationship between the B-scan OCT image features and histology of malignant human
colorectal tissues, also en-face OCT image and the endoscopic image pattern. The in-vitro experiments were performed
by a swept-source optical coherence tomography (SS-OCT) system; the swept source has a center wavelength at 1310
nm and 160nm in wavelength scanning range which produced 6 um axial resolution. In the study, the en-face images
were reconstructed by integrating the axial values in 3D OCT images. The reconstructed en-face images show the same
roundish or gyrus-like pattern with endoscopy images. The pattern of en-face images relate to the stages of colon cancer.
Endoscopic OCT technique would provide three-dimensional imaging and rapidly reconstruct en-face images which can
increase the speed of colon cancer diagnosis. Our results indicate a great potential for early detection of colorectal
adenomas by using the OCT imaging.