| [ Summary ] |
We examined the usefulness of pit pattern diagnosis using both high-resolution ordinary and magnifying colonoscopy. As to the pit pattern classification, we used the type reported previously by Kudo. The cancer rates (submucosal cancer rates) seen in pit pattern results obtained from magnifying colonoscopic observations were IIIL 34/95:36% (0%), IIIS 16/39:41% (3%), IV 11/16:69% (6%), VA 20/22:91% (27%), VN 25/25:100% (92%), respectively. The incidence of massive submucosal cancer rates in V pit patterns was VA 2/22 (9%) and VN 21/25 (84%), respectively. On the other hand, the corresponding rates between magnifying colonoscopic observations and ordinary observations, using the high-resolution colonoscope, are 9/12 (75%)in II, 42/59 (71%) in IIIL, 0/70 (0%) in IIIs, 6/8 (75%) in IV, 1/20 (5%) in VA, 20/33 (61%) in VN, respectively. The number of accurate pit pattern diagnoses from ordinary observations, using the high-resolution colonoscope is very low especially in IIIs and VA pit patterns. Furthermore, even if the pit pattern is VN, about 40% of lesions can not be detected. In conclusion, pit pattern diagnosis using magnifying colonoscope for colorectal tumors is useful in histologic diagnosis and invasion depth prediction. Ordinary observation using a high-resolution colonoscope is partially useful in the diagnosis of relatively large pit patterns (II,IIIL, IV), however, magnifying observation is essential for correct pit pattern diagnosis. |