4487 A novel approach to detecting colorectal cancers: direct identification of histology by magnifying endoscopy.

Abstract

Background: By magnifying endoscopic examination with dye spraying method, the openings of colonic glands, "pits" of various shapes and sizes, are found on the surface of colonic mucosa. In our data, pits of roundish, asteroid, tubular, and branching shape are seen on the surface of benign lesions. On the other hand, pits of irregular and complicated shapes can be seen on the surface of early cancers. Accordingly, it is important to clarify whether surface structure of colorectal cancer really reflects its histological findings. Aims: To examine whether complexity of pits revealed by magnifying endoscopic findings is correlated with that of histological findings, finding of the glandular structure and cellular atypia. Methods: 36 submucosal invasive cancers, 27 mucosal cancers, 40 adenomas and 10 specimens of normal mucosa were investigated. Pits of all lesions were examined by means of the magnifying video endoscope (Olympus, 240-Z) as well as the stereomicroscope after endoscopic or surgical removal. Histological sections were prepared from the area where pits of irregular shapes were located. Complexity of shapes of pits and histological glandular structures were evaluated by fractal dimension (FD) with the boxcounting method. In the present study irregular pits were morphologically classified into three types: irregularly roundish (IR), irregularly polygonal (IP) and irregularly branching (IB) pits. Results: 1) Fractal dimensions of pits were significantly correlated with those of glandular structures as revealed by the analysis of variance in regression (p<0.0001). 2) Fractal dimensions of (IR), (IP) and (IB) were 1.41±0.06, 1.66±0.09, and 1.61±0.05 respectively, all of which were higher than the values of benign lesions (p<0.001). 3)It was suggested that the high value of FD became the high cellular atypia became. Conclusions: Magnifying endoscopic findings are really correlated with histological atypia. Therefore, one of the most outstanding advantages of magnifying endoscopy lies in accurate detection of colorectal cancers without taking biopsy samples. It may be said that this will open up new vistas of detecting colorectal cancers especially at their early stages.