Light-induced fluorescence of human colon tissue: dependence on histological and histochemical properties studied by means of a simplified model for simulation

In an attempt to evaluate the role of the histological and histochemical features of adenocarcinoma and normal tissue on their fluorescence spectral patterns, we developed a Monte Carlo model to simulate the fluorescence emission from tissue. According to histology, normal colon and adenocarcinoma were considered composed of three and two tissue layers, respectively (i.e., superficial epithelium, mucosa and submucosa; tumor mass and submucosa). Characterization of the fluorescence pattern of the tissue layers as well as of several histological components was performed by spectrofluorometric analysis on ex vivo samples. Results obtained from differently modelling the morphology and histological arrangement of colon suggest the following remarks. The decrease in fluorescence intensity observed in passing from normal to abnormal tissue could be ascribed mainly to a modification in morphology. When carcinomatous tissue is involved a modification in the spectral shape is also expected.