Patterns of mucus secretion in the colonic epithelium in familial polyposis.

Patterns of mucus secretion were investigated, by histochemical methods, in 24 colectomy specimens resected for familial polyposis coli. In this pre-malignant condition, mucus secretion contained an increased proportion of sialomucins as compared with normal colonic mucosa where sulphomucins predominate. These mucin changes (a) were more extensive in the left colon than in the right; (b) although consistently present in the mucosa adjacent to carcinomas, independent of their site, and around large polyps, they were also seen in patches of mucosa distant from the neoplastic growth; (c) they were more marked in the non-involved mucosa from patients who had developed carcinoma than in the non-cancer group. It was not possible to relate the type of mucin secreted and the degree of dysplasia. Similar alterations in mucus secretion have been previously described in colonic mucosa harbouring carcinoma both in humans and experimentally in rats, suggesting a relationship between altered glycoprotein synthesis and malignancy. The present results add further evidence to this hypothesis.