Pseudoinvasion of the colorectal polypoid tumors: serial section study of problematic cases.

摘要: Ten cases of endoscopically removed colorectal polypoid tumors exhibiting lobular growth patterns in the submucosa without prominent desmoplastic changes interstitium were investigated using serial sections, and four confirmed to be pseudoinvasion. The pattern these (pseudoinvasive tumors) was morphologically compared with other six (microinvasive which obviously infiltrating foci seen minimal ranges. In pseudoinvasive tumors, intramucosal tumor tissue spread into through narrow gap muscularis mucosae formed a lobulated nodule larger than mucosae. This suggested that squeezing herniated by at crucial forming typical feature maximum diameters (G) submucosal (N) measured under microscope between both groups. mean N/G ratio (1.73 +/- 0.46) indicated significantly higher value microinvasive (1.04 0.06; P < 0.01). could one indices used distinguish from tumors.