4485 Incidence of depressed colorectal neoplasia in southern brazil.

Abstract

Flat and depressed colorectal lesions despite being increasingly reported in Japan, are still a matter of controversy in western countries and the true incidence of these lesions is poorly undestood. The AIM of this study is to evaluate the incidence of depressed lesions diagnosed on routine colonoscopy in a brazilian endoscopic center. METHODS During January 1996 to May 1999, all total colonoscopies performed with magnifying colonoscope(Fujinon410CM) allowing up to 40x magnification of the standard videoimage, were included in the analysis. Patients with familial polyposis and inflammatory bowel disease were excluded. Macroscopically, colorectal neoplastic lesions were classified as polyps, flat elevated lesions, depressed lesions(IIc) and lateral spreading tumors. On colonoscopy the lesions were examined in detail by chromoscopy with indigo-carmine 2% and/or pyoktanin-blue 0.5% and the pit pattern on the surface of the lesion was determined as Kudo's classification. All lesions were resected by polypectomy or endoscopic mucosal resection (EMR). RESULTS Among 1930 total colonoscopies, 13 depressed lesions (0.7%) were diagnosed. Size of the lesions varied from 1.4 to 7mm in diameter. Seven lesions were located in the sigmoid, 3 in ascending, 2 in the transverse and 1 in the descending colon. Histologic diagnosis was carcinoma in 6 lesions, adenoma with high-grade dysplasia in 5 lesions and low grade in 2 lesions. Pit pattern of the depressed lesions were IIIs in 9 lesions, V in 3 lesions and IV in one lesion. Other diagnosed lesions in this group of patients were 1594 polyps, 63 flat elevated lesions and 51 lateral spreading tumors. CONCLUSIONS Depressed colorectal neoplasia exhibiting the same features as reported by japanese investigators were also diagnosed in our group of patients. Despite the small size and low incidence (0.7%) of depressed lesions, the high frequency of carcinoma and high-grade dysplasia diagnosed in these lesions emphasize the need for the endoscopic diagnosis and resection of these lesions to prevent colorectal cancer. Flat and depressed colorectal lesions despite being increasingly reported in Japan, are still a matter of controversy in western countries and the true incidence of these lesions is poorly undestood. The AIM of this study is to evaluate the incidence of depressed lesions diagnosed on routine colonoscopy in a brazilian endoscopic center. METHODS During January 1996 to May 1999, all total colonoscopies performed with magnifying colonoscope(Fujinon410CM) allowing up to 40x magnification of the standard videoimage, were included in the analysis. Patients with familial polyposis and inflammatory bowel disease were excluded. Macroscopically, colorectal neoplastic lesions were classified as polyps, flat elevated lesions, depressed lesions(IIc) and lateral spreading tumors. On colonoscopy the lesions were examined in detail by chromoscopy with indigo-carmine 2% and/or pyoktanin-blue 0.5% and the pit pattern on the surface of the lesion was determined as Kudo's classification. All lesions were resected by polypectomy or endoscopic mucosal resection (EMR). RESULTS Among 1930 total colonoscopies, 13 depressed lesions (0.7%) were diagnosed. Size of the lesions varied from 1.4 to 7mm in diameter. Seven lesions were located in the sigmoid, 3 in ascending, 2 in the transverse and 1 in the descending colon. Histologic diagnosis was carcinoma in 6 lesions, adenoma with high-grade dysplasia in 5 lesions and low grade in 2 lesions. Pit pattern of the depressed lesions were IIIs in 9 lesions, V in 3 lesions and IV in one lesion. Other diagnosed lesions in this group of patients were 1594 polyps, 63 flat elevated lesions and 51 lateral spreading tumors. CONCLUSIONS Depressed colorectal neoplasia exhibiting the same features as reported by japanese investigators were also diagnosed in our group of patients. Despite the small size and low incidence (0.7%) of depressed lesions, the high frequency of carcinoma and high-grade dysplasia diagnosed in these lesions emphasize the need for the endoscopic diagnosis and resection of these lesions to prevent colorectal cancer.