Differentiation‐associated changes in mucin glycoprotein antigenicity in mucosa adjacent to rare gastrointestinal tract tumours of non‐mucosal origin

Abstract

We have investigated changes in mucin antigenicity and morphology in the perineoplastic mucosa adjacent to rare, predominantly non-mucosal gastrointestinal (GI) tumours. Twenty-nine tumours of small and large intestine, including primary mesenchymal and ectodermal tumours, were examined immunohistochemically using 11 monoclonal antibodies (MAbs) raised against SIMA and LIMA (small and large intestinal mucin antigens). Non-epithelial GI tumours were essentially non-reactive, while adjacent mucosa showed altered mucin expression and morphology, in particular, features of transitional mucosa (TM). Combinations of different SIMA epitopes were detected adjacent to all colorectal tumours, and, similarly, LIMA epitopes adjacent to small intestinal tumours. Specific patterns adjacent to certain tumours may reflect influences of factors produced by individual tumours on mucin composition. Altered antigenicity and morphology in TM thus appear to be reactive changes in response to a wide range of GI tumours, presumably as a consequence of factors secreted by the tumour and/or a host response to the tumour.

Epithelial salivary gland tumours. An immunohistological and prognostic investigation

“…As discussed previously our material is too small to allow definite conclusions (11,111). Our findings that sTn and Tn antigens were expressed in the remnants of pleomorphic adenoma in carcinoma in pleomorphic adenoma do, however, not necessarily reflect a premalignant event, but may reflect a more general reactive response to factors secreted by the carcinomas as discussed by Pilbrow et al (1993) in a study of the gastrointestinal tract. It is also important to note that atypical cells and hyalinization are regarded as the earliest signs of malignant transformation in pleomorphic adenomas (Foote andFrazell 1973, Auclair and.…”