3391 Clinical significance of magnifying observation using videocoloscope for the invasion depth diagnosis of colorectal neoplasia.

Recent advances of magnification of videoendoscopy have enabled the detailed observation of colorectal tumor surface. The AIM of this study is to clarify the clinical significance of the pit pattern diagnosis for colorectal tumors using the magnifying videocolonoscope (CF-200Z, CF-Q240Z; Olympus or EC-410CM, EC-410ZM; Fujinon). METHODS : We examined the pit pattern of tumor surface in 342 colorectal adenomas and early carcinomas in relation to the pathologic features using above mentioned videocolonoscope with indigocarmine dye spraying or crystal violet staining methods. Regarding the pit pattern classification, we used the type (I, II, IIIL, IIIS, IV, VA and VN), reported previously by Kudo. Furthermore, we subclassified the VN pit pattern based on the non-structure area on the tumor surface into grade A (small), B (middle) and C (large). RESULTS : The cancer rate (submucosal cancer rate) in each pit pattern finding obtained from magnifying colonoscopic observation was IIIL 49/150: 33% (2%), IIIS 15/36: 42% (3%), IV 16/30: 53% (3%), VA 53/58: 91% (19%), VN 35/39: 90% (80%), respectively. The incidence of submucosal massive cancer in V pit pattern was VA 3/58 (5%), VN 31/39 (80%), respectively. On the other hand, according to our new classification, submucosal massive cancer rate in each Grade A, B and C of VN pit pattern is 3/8 (38%), 16/17 (94%) and 14/14 (100%), respectively. CONCLUSION : Pit pattern diagnosis using magnifying videocolonoscope for colorectal tumor is useful in the histologic diagnosis and invasion depth prediction. Especially, Grade B and C of VN pit pattern are the definite indicators of submucosal massive colorectal carcinoma that can't be indicative for the curative endoscopic resection.