| [ Summary ] |
Endoscopic diagnosis of submucosal invasive cancer is made on the basis of sclerotic changes, radiating folds, changes in expansion etc. On the other hand, we examined colorectal tumor surface structures (pit pattern) using a stereomicroscope and a magnifying electric endoscope, and comparing histological findings. We carried out six types of pit pattern classification, and divided type V into two subclasses, an irregular or amorphous pit pattern (type VA) and a secondly nonstructural surface(type VN). First the type VA lesions suggested mucosal cancer (40.8%) and invasive cancer (36.7%), but the type VN lesions were classified mainly as invasive cancer (62.5%). We observed the type VN lesions using a stereomicroscope, and found scratch patterns on there surfaces. In cases a submucosal invasive cancer we proposed a classification of the degree of depth of submucosal invasion. The type VN lesions with scratch signs (scratch sign positive) suggested that cancer cells reached the depth of middle third of the submucosal area (77.8%). The type VN lesions without scratch signs (scratch sign negative) suggested that cancer cells reached the lower third depth (87.5%).
Endoscopic diagnosis of pit patterns related to stereomicroscopic diagnosis, had a 89.6% relationship. The pit pattern diagnosis was a helpful diagnostic clue for endoscopic examination of invasive cancer.But we must be careful of amorphism, non-structures and mucus interference under observation in vivo. It is important that we have knowledge about the weak points of endoscopic examination. |