ultraviolet laserinduced fluorescence of colonic polyps ultraviolet laserinduced fluorescence was examined in vivo to determine whether the technique can reliably distinguish between hyperplastic and adenomatous polyps of the colon spectra from 86 normal colonic sites 35 hyperplastic polyps and 49 adenomatous polyps were recorded in vivo polyp type was independently determined by two senior pathologists who were unaware of the fluorescence measurement a multivariate linear regression analysis was used to differentiate spectra from hyperplastic and adenomatous polyps and resulted in a sensitivity specificity predictive value positive and predictive value negative for identifying adenomatous polyps of 86 80 86 and 80 respectively these values were not significantly different from the accuracy of routine clinical pathology thus ultraviolet laserinduced fluorescence appears to show promise as a means for distinguishing tissue types however further experience is needed before its routine clinical use can be recommended significant changes in the fluorescence spectra occurred postmortem suggesting that future studies of laserinduced fluorescence of colonic tissue must use data acquired in vivo