Abstract
Many studies of the experimental hepatocarcinogenesis implicated the hyperplastic nodules as a premalignant lesion. In addition, it has been shown that all hyperplastic nodules do not always progress to the liver cell carcinomas. In the present study, the liver surface of rats fed with 0.005% diethylnitrosamine was studied laparoscopically with electroendoscope (EES-50 A, Toshiba-Machida Co.). The electroendoscope used in this study enabled us to analyze quantitatively the color of the liver surface, by RGB values and perceptual parameters-HSI. The laparoscopic examination revealed that the hyperplastic nodules were noted after 10 weeks and liver cell carcinomas after 13 weeks of DEN feeding. Both the hyperplastic nodules and liver cell carcinomas did not take up indocyanine green (ICG), while surrounding liver tissues did. But, the color analysis based on HSI signals showed that the capacity of ICG uptake in hyperplastic nodules had still been preserved, compared to the lack of ICG uptake in liver cell carcinomas. From these results, it was suggested that the hyperplastic nodules might be precancer-ous in the rat hepatocarcinogenesis.
