Abstract

Background
/Aims: To investigate the morphological and histopathological associations between an individual pit seen on stereomicroscopy or magnifying colonoscopy and an individual crypt seen in histological sections of colorectal tumors. Methods: Fifty two colorectal lesions were examined by colonoscopy. The mucosal pits of the lesions were observed using a magnifying colonoscopy with a zoom 1 to 100 magnification after administering indigo carmine spray. The pits of the excised specimens were observed by using a stereomicroscopy after 0.2% cresyl violet stain. The pit patterns were classified into six types: normal round pit (I); asteroid pit (II); small round pit (IIIs); large tubular pit (IIIL); gyrus-like pit (IV); and non-structural pattern or amorphysm (V). Histologic diagnoses were determined by H&E staining under light microscopy. Results: The histologic findings according to the pit patterns were 1 chronic nonspecific inflammation and 1 submucosal tumor in 2 cases with type I pit pattern; 4 hyperplastic polyps in 4 cases with type II; 1 hyperplastic polyp, 16 adenomas with low-grade dysplasia, 3 adenomas with high-grade dysplasia, and 1 carcinoma in situ in 21 cases with type IIIL; 4 adenomas with low-grade dysplasia, 3 adenomas with high-grade dysplasia, and 4 carcinoma in situ in 11 cases with type IV; 1 adenoma with low-grade dysplasia in 1 case with type II IIIL; 3 adenomas with low-grade dysplasia, 4 adenomas with high-grade dysplasia, and 2 carcinoma in situ in 9 cases with type IIIL IV; 1 adenoma with high-grade dysplasia, 2 carcinoma in situ, and 1 adenocarcinoma in 4 cases with type IV V. In assessing the histologic findings according to pit pattern by stereomicroscopy, the overall diagnostic predictive value was 82.6% (43/52), and the diagnostic accuracy in differential diagnosis between nonneoplastic and neoplastic lesions was 98% (51/52). The ratio of agreement of the pit pattern between the magnifying colonoscopy and the stereomicroscopy was 68% (17/25). Conclusions: The results suggest that there was a close correlation between the pit patterns and the histologic findings of colorectal tumors, and that the observation of pit patterns of colorectal lesions provides a differential diagnosis between neoplastic and nonneoplastic lesions. (Korean J Gastrointest Endosc 19: 904∼910, 1999)

• Keywords: Pit pattern, Stereomicroscopy, Magnifying colonoscopy, Colorectal tumor;