Retrospective histochemical study of mucosubstances in adenocarcinomas of the gastrointestinal tract.

Use of the PATS/KOH/PAS and PB/KOH/PAS techniques and the diamine method (Spicer 1965) together with the demonstration of metachromasia with toluidine blue pH 3.0, for the study of carbohydrates in a retrospective study of gastric and colorectal adenocarcinomas, disclosed an increase in the sulphate content and the absence of O-acylated sialomucins in the majority of gastric adenocarcinomas. In the colorectal tumours there is no change in the degree of sulphation normally present in this area, but the degree of acylation of the sialic acid in adenocarcinoma is very different to that of normal mucosa and appears related to the degree of differentiation of the tumour. The mucosa adjacent to tumours from both areas were also studied, as well as gastric intestinal metaplasia.