3432 Spatial arrangement of microvasculature accounts for difference in endoscopic color between colonic carcinoma and normal mucosa

Background: We have previously demonstrated that the degree of endoscopic surface redness was significantly larger in colonic carcinoma than in normal mucosa. Aim: The aim of this study was to correlate endoscopic redness with histological variables, concerning microvasculature in the tissue of colonic carcinoma and normal mucosa. Methods: Five patients with colorectal carcinoma were studied. They underwent colonoscopy for pictures of the growth and normal appearing parts more than 5 cm apart from the growth. Endoscopic pictures were processed for an index of hemoglobin (IHB) as the degree of surface redness in each region of interest by an image processor. The surgical specimens, sliced were stained with CD34 for vascular counts (/mm 2 ) and the total cross sectional area of vasculature per the unit area of region of interest (%VA). In this study, the spatial direction of longitudinal axis of each vascular canal (θ) was reconstructed from a shape of vascular cross section. When the direction is vertical to the mucosal surface (θ=0 degree), the vessel is recognized as a point on endoscopy. While, when it is parallel to the mucosal surface (θ=90 degree), the vessel is recognized as a line. Results: IHB was significantly larger in colonic carcinoma (37.0± 8.1) than in normal mucosa (29.7±5.8, p=0.049). Vascular counts was large in colonic carcinoma (274±183) compared with that in normal mucosa (203±58), but it did not reach the significant level (p =0.176). %VA also was larger in carcinoma (3.8±2.0) than in normal mucosa (3.1±1.5), although it was not statistically significant (p=0.253). While, θ was significantly larger in carcinoma (52.1±6.7) than in normal mucosa (44.0±5.8, p=0.021). Conclusions: Colonic carcinoma was significantly more red than normal mucosa. A novel histological variable, the spatial arrangement of microvasculature can reasonably account for this difference along with vascular counts and vascular bed area.