Narrow-band imaging magnification predicts the histology and invasion depth of colorectal tumors

Abstract

There are several reports concerning the differential diagnosis of non-neoplastic and neoplastic colorectal lesions by narrow-band imaging (NBI). However, there are only a few NBI articles that assessed invasion depth. To determine the clinical usefulness of NBI magnification for evaluating microvessel architecture in relation to pit appearances and in the qualitative diagnosis of colorectal tumors. A retrospective study. Department of Endoscopy, Hiroshima University, Hiroshima, Japan. A total of 289 colorectal lesions were analyzed: 12 hyperplasias (HP), 165 tubular adenomas (TA), 65 carcinomas with intramucosal to scanty submucosal invasion (M-SM-s), and 47 carcinomas with massive submucosal invasion (SM-m). Lesions were observed by NBI magnifying endoscopy and were classified according to microvessel features and pit appearances: type A, type B, and type C. Type C was divided into 3 subtypes (C1, C2, and C3), according to the detailed NBI magnifying findings of pit visibility, vessel diameter, irregularity, and distribution. These were compared with histologic findings. Histologic findings of HP and TA were seen in 80.0% and 20.0%, respectively, of type A lesions. TA and M-SM-s were found in 79.7% and 20.3%, respectively, of type B lesions. TA, M-SM-s, and SM-m were found in 21.6%, 29.9%, and 48.5, respectively, of type C lesions. HPs were observed significantly more often than TAs in type A lesions, TAs were observed significantly more often than carcinomas in type B lesions, carcinomas were observed significantly more often than TAs in type C (P < .01). TA, M-SM-s, and SM-m were found in 46.7%, 42.2%, and 11.1% of type C1 lesions, respectively. M-SM-s and SM-m were found in 45.5% and 54.5%, respectively, of type C2 lesions. SM-m was found in 100% of type C3 lesions. TAs and M-SM-s were observed significantly more often than SM-m in type C1 lesions, and SM-m were observed significantly more often than TAs and M-SM-s in type C3 lesions (P < .01). NBI magnification findings of colorectal lesions were associated with histologic grade and invasion depth.