HIGH-RESOLUTION CHROMOENDOSCOPY FOR THE DIAGNOSIS OF DIMINUTIVE COLONPOLYPS - IMPLICATIONS FOR COLON-CANCER SCREENING

Background & Aims: A visual, nonbiopsy technique that could reliably d etermine the histology of diminutive colorectal polyps could greatly r educe the cost of colon cancer screening. This study was designed to r eport our experience using a high-resolution colonoscope combined with indigo carmine dye to diagnose diminutive colorectal polyps. Methods: Colonoscopy using a Fujinon EC-400 HM/HL was performed in 36 patients with polyps <10 mm in diameter. Polyps from the first 12 patients (ph ase 1) were sprayed with 10 mL of 0.2% indigo carmine dye, and a biops y was performed or a specimen removed and submitted for histological a nalysis. The morphological data were used to predict polyp histology i n the subsequent 24 patients (phase 2). Results: Hyperplastic polyps h ad a characteristic surface ''pit pattern'' of orderly arranged ''dots '' that resembled the surrounding, nonpolypoid mucosa. Adenomatous pol yps had surface ''grooves'' or ''sulci.'' Sensitivity and specificity of our techniques in distinguishing adenomatous from nonadenomatous co lorectal polyps were 93% and 95%, respectively. Conclusions: High-reso lution chromoendoscopy provides morphological detail of diminutive col orectal polyps that correlates well with polyp histology. If incorpora ted into colon cancer screening, these techniques may limit the need f or biopsy and/or subsequent colonoscopy and ultimately decrease costs.