Abstract 4418: The histopathological characteristics of mucin-depleted foci in patients with sporadic colorectal cancer

Abstract

Abstract Introduction: In experimental models, Mucin-depleted foci (MDF), formed by dysplastic crypts devoid of mucin production have been recognized to be correlated with colorectal carcinogenesis and to serve as preneoplastic lesions of colorectal cancer (CRC). In humans, there is only one report of identification of MDF mainly in patients with familial adenomatous polyposis, however the histological characteristics of human MDF was not discussed sufficiently in this report. Therefore, we conducted this study to identify MDF in sporadic CRC patients and to evaluate the histological characteristics of human MDF. Materials and Methods: Colonic samples from 53 patients of sporadic CRC were stained with Alcian blue and examined for the presence of MDF. Subsequently, the samples were also examined for the presence of aberrant crypt foci (ACF) by methylene blue staining. We classified MDF into two categories, namely, flat-MDF and protruded-MDF (having the characteristics of both ACF and MDF), and analyzed their histological characteristics. Results: We found a total of 354, 41 and 19 colonic mucosal lesions with a mean multiplicity of 44, 38.9 and 66.9 crypts (ACF, flat-MDF and protruded-MDF, respectively). The density of MDF was 0.0082 lesions/cm2. ACF identified in sporadic CRC patients corresponded to hyperplastic or non-dysplasic lesions. On the other hand, MDF (both of flat-MDF and protruded-MDF) identified in these patients corresponded to low-grade dysplasia. In addition, we found that Paneth cell metaplasia and inflammatory cell infiltration were specific histological features of MDF. These histopathological characteristics have been reported to be associated with the development of CRC. Conclusions: This is the first report of a study conducted to investigate the density and histopathological characteristics of MDF in a large sample of sporadic CRC patients. Our results indicate that MDF might represent preneoplastic lesions in human colorectal carcinogenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4418. doi:1538-7445.AM2012-4418