Colonic mucosa adjacent to adenomas and hyperplastic polyps—a morphological and histochemical study

Abstract

The morphological and histochemical features of colonic mucosa adjacent to 142 adenomas and 31 hyperplastic polyps were studied. Three predominant patterns were identified: (1) normal mucosa, showing normal histological architecture and secretion of sulphomucins; (2) N+ type, histologically normal mucosa with predominance of sialomucins; (3) transitional mucosa; hyperplastic mucosa secreting sialomucins. Hyperplastic changes were observed in the immediate neighbourhood or at the base of adenomas and were more frequent and extensive near large adenomas than around smaller lesions. Sialomucins were often predominant in the mucosa adjacent to large adenomas, but N+ type mucosa was also seen near minute adenomas and hyperplastic polyps and remote from polypoid lesions. Moreover, both hyperplastic and secretory changes were more frequent in the left colon than in the right. These findings seem to suggest that mucosal hyperplasia more likely represents a local change, parallel with or secondary to tumour development rather than a pre-adenomatous lesion. Secretory modifications are widespread and may result from the action of various factors among which carcinogens cannot be excluded.

Detection of colorectal dysplasia using fluorescently labelled lectins

“…Hyperplasia is often accompanied by an increase in acidic mucins that have high levels of sialic acids (sialomucins) 27 , a trend also observed in this study ( Fig. 4 ).…”

“…Mucins cover the entire colonic mucosa and changes in their expression and glycosylation are associated with progression to CRC 20 21 and can be associated with a poor prognosis 22 23 24 25 . Sialic acid content changes in colonic neoplasia 26 and hyperplastic tissue secretes mucus rich in sialomucins 27 . Therefore imaging agents that bind specific glycan moieties may be useful in distinguishing normal from dysplastic tissues as well as hyperplasia from dysplasia.…”

Induction of Angiogenesis by Hyperplastic Colonic Mucosa Adjacent to Colon Cancer

“…[1][2][3] Several analyses concluded that this transitional mucosa contains more immature and intermediate cells and fewer differentiated cells and more sialomucin secretion than does nonhyperplastic normal mucosa, whose cells predominantly secrete sulfomucins. 4 -8 Whether the hyperplastic mucosa adjacent to colon cancer is a precancerous lesion 4,9,10 or a response to the growing cancer [11][12][13][14] or to microorganisms, such as Citrobacter freundii in humans 15,16 and Citrobacter rodentium in mice 17 has been debated. Hyperplasia of the ductal epithelium is often found adjacent to mammary adenocarcinoma and pancreatic cancer.…”

A morphometric assessment of transitional mucosa in the colon

“…These findings have suggested that the changes are a secondary phenomenon. It has also been pointed out that in certain instances, hyperplasia and mucin changes do not always occur together (Listinsky & Riddell 1981, Franzin et al 1983, Lanza et al 1985 and this further supports the concept that these changes are secondary.…”

“…This has not been reported. Secondly, a majority of adenocarcinomas and dysplastic foci in polyps actually secrete sulphomucins or show mixed secretion patterns as opposed to the abnormal sialomucins typical of transitional mucosa (Lanza et al 1985, Allen, Connolly & Biggart 1988. Allen and co-workers (1988) point out that this abnormal change to sialomucins in transitional mucosa and reversion to sulphomucins in dysplasia and carcinoma might be unusual for the proposed sequence of malignant transformation.…”