Abstract
Twenty-six cases of gastrointestinal advanced cancer (11 gastric, two intestinal and 13 colonic cancers) were examined for serosal invasion by spraying with a 0.1% methylene blue dye under magnifying microscope or laparoscope. Methylene blue staining showed fine structures of serosal surface and small areas of nodular blue staining were observed in some cases. After marking these areas with permapent ink under microscope, they revealed cancer invasion to the serosa in the histological cross sections. Judging from the staining, nine cancers were invading and 15 were not invading the serosa. These results obtained in these cases were in agreement with those of histological diagnosis except two cases. In about half cases of this series, serosal invasion could be hardly diagnosed macroscopically. Identification of serosal invasion with methylene blue dye is a very easy and rapid technique with a higher sensitivity and specificity than the surgeon's clinical diagnosis. More precise diagnosis with this technique could contribute to the decision-making of intra and post-operative adjuvant treatments.
