Prediction of histology and invasive depth of colorectal neoplasia based on morphology of surface depression using magnifying chromocolonoscopy

Abstract

Background and study aims: Estimation of histology and depth of invasion in early colorectal neoplasia is essential for patient treatment. We therefore conducted a prospective study to examine whether the morphology of depression area contained at the surface of colorectal neoplasia can be used for predicting the histology and invasive depth.

Methods: A series of 228 consecutive patients with 296 colorectal lesions were studied. All lesions were evaluated by magnifying chromocolonoscopy. Surface depression contained in the lesions was noted and the depressive morphology was further divided into two subgroups of type I and type II. All of the lesions were resected endoscopically or surgically and examined histologically for comparison.

Results: A total of 296 lesions were evaluated, of which 66 (22.3%) contained an area of central depression, including 43 in nonpolypoid (flat and depressed) lesions (66%) and 23 in polypoid (10%). The overall accuracy of depressive morphology for distinction between low-grade dysplasia and high-grade dysplasia/invasive cancer, and between m-sm1 and sm2-sm3 was 86.4% and 84.8%, respectively.

Conclusions: Depression was predominantly contained in nonpolypoid colorectal neoplasia. Morphology of depression observed by magnifying chromocolonoscopy could be used as a complementary method to assess the degree of atypia and invasive depth in colorectal neoplasia.