Patterns of mucin secretion in neoplastic and non-neoplastic diseases of the colon.

Changes in the pattern of sulfomucin and sialomucin secretion and height of large bowel mucosa have been described adjacent to primary colonic adenocarcinomas and adenomas, and called "transitional" mucosa. These changes were initially thought to be specific preneoplastic changes. In this study "transitional" changes in colonic and rectal mucosa were found in some cases overlying benign mesenchymal tumors, metastatic tumors from noncolonic sites, and sites of endometriosis, as well as adjacent to primary colonic and rectal neoplasms. These findings suggest that although these changes may be found adjacent to primary large bowel neoplasms, they are frequently secondary reactive rather than primary preneoplastic phenomena. In addition, the thickness of the mucosa and the accompanying pattern of mucin secretion usually seen in transitional mucosa may be dissociated.