4519 Clinical significance of magnifying colonoscopy in superficial-type colorectal lesions.

Abstract

Background/Aims: Recently,the frequency of detection of small superficialtype colorectal adenocarcinoma was increased. It is still difficult to detect such lesions and make differential diagnosis from nonneoplastic lesions, endoscopically. Magnifying colonoscopy was developed for detailed examination of the colorectal lesions by means of observation of pit patterns on those surfaces. This study was designed to clarify the usefulness of magnifying colonoscopy for evaluating superficial-type lesions of colorectum. Materials/Methods: Three hundred and forty two lesions, which were suggested superficial-type neoplastic lesions on conventional colonoscopy, were analyzed according to their pit patterns using magnifying colonoscopy. Pit patterns was classified into six types; I (normal round pits), II (large starry-shaped pits), IIIs (small round pits), IIIL (large round or tubularshaped pits), IV (branched or gyrus-like pits), V (irregular shaped or nonstructural pits). The histopathologic diagnoses were determined from the tissue of lesions obtained by endoscopic biopsy, polypectomy or mucosal resection. Results: 1) Their morphologic features were IIa in 205 lesions, IIa+IIc in 68, IIb in 21, IIc in 17, laterally spreading tumor(LST) in 31. 2) Pit patterns were type I in 38 lesions, type II in 76, type IIIs in 15, type IIIL in 197, type IV in 11, type V in 5. 3) Histologic findings according to pit pattern showed that 83.3%(95/114) of the lesions with type I or II were nonneoplastic lesions, 95.2%(217/228) of the lesions with type IIIs or IIIL, IV, V were neoplastic lesions(adenomas or adenocarcinomas). Overall diagnostic accuracy of magnifying colonoscopy in differential diagnosis between neoplastic and nonneoplastic lesions was 91.2%(312/342). 4) High grade dysplasia or adenocarcinoma were present in 0%(0/114) of lesions with type I or II pit patterns, 26.7%(4/15) of type IIIs, 4.6%(9/197) of type IIIL, 27.3%(3/11) of type IV, 80.0%(4/5) of type V. Conclusions: There was a good correlation between pit pattern and the histologic findings of superficial-type colorectal lesions, and observation of pit pattern of superficialtype colorectal lesions using the magnifying endoscope is useful not only in differential diagnosis between neoplastic and nonneoplastic lesions, but also in assesment of malignant potential in superficial-type neoplastic lesions. Background/Aims: Recently,the frequency of detection of small superficialtype colorectal adenocarcinoma was increased. It is still difficult to detect such lesions and make differential diagnosis from nonneoplastic lesions, endoscopically. Magnifying colonoscopy was developed for detailed examination of the colorectal lesions by means of observation of pit patterns on those surfaces. This study was designed to clarify the usefulness of magnifying colonoscopy for evaluating superficial-type lesions of colorectum. Materials/Methods: Three hundred and forty two lesions, which were suggested superficial-type neoplastic lesions on conventional colonoscopy, were analyzed according to their pit patterns using magnifying colonoscopy. Pit patterns was classified into six types; I (normal round pits), II (large starry-shaped pits), IIIs (small round pits), IIIL (large round or tubularshaped pits), IV (branched or gyrus-like pits), V (irregular shaped or nonstructural pits). The histopathologic diagnoses were determined from the tissue of lesions obtained by endoscopic biopsy, polypectomy or mucosal resection. Results: 1) Their morphologic features were IIa in 205 lesions, IIa+IIc in 68, IIb in 21, IIc in 17, laterally spreading tumor(LST) in 31. 2) Pit patterns were type I in 38 lesions, type II in 76, type IIIs in 15, type IIIL in 197, type IV in 11, type V in 5. 3) Histologic findings according to pit pattern showed that 83.3%(95/114) of the lesions with type I or II were nonneoplastic lesions, 95.2%(217/228) of the lesions with type IIIs or IIIL, IV, V were neoplastic lesions(adenomas or adenocarcinomas). Overall diagnostic accuracy of magnifying colonoscopy in differential diagnosis between neoplastic and nonneoplastic lesions was 91.2%(312/342). 4) High grade dysplasia or adenocarcinoma were present in 0%(0/114) of lesions with type I or II pit patterns, 26.7%(4/15) of type IIIs, 4.6%(9/197) of type IIIL, 27.3%(3/11) of type IV, 80.0%(4/5) of type V. Conclusions: There was a good correlation between pit pattern and the histologic findings of superficial-type colorectal lesions, and observation of pit pattern of superficialtype colorectal lesions using the magnifying endoscope is useful not only in differential diagnosis between neoplastic and nonneoplastic lesions, but also in assesment of malignant potential in superficial-type neoplastic lesions.