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Adenocarcinoma of colon differentiating as dome epithelium of gut‐associated lymphoid tissue
Author(s) -
Jeremy R. Jass,
Leonie Constable,
Robert L. Sutherland,
CM Winterford,
Michael D. Walsh,
Joanne P. Young,
Barbara A. Leggett
Publication year - 2000
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1046/j.1365-2559.2000.00864.x
Subject(s) - pathology , gut associated lymphoid tissue , epithelium , adenocarcinoma , microsatellite instability , biology , intestinal epithelium , intraepithelial neoplasia , immunohistochemistry , ascending colon , mucin , submucosa , colorectal cancer , lymphatic system , cancer , medicine , prostate , allele , biochemistry , gene , microsatellite , genetics
Aims An early adenocarcinoma of the ascending colon was confined to a mass of gut‐associated lymphoid tissue (GALT). The first description of an adenocarcinoma of colon differentiating as dome epithelium is presented. Methods and results A plaque‐like carcinoma was identified opposite the ileocaecal valve in an asymptomatic 56‐year‐old man with a family history of colorectal cancer. Malignant epithelium was confined to a mass of GALT filling but limited to the submucosa. Characterization of the neoplasm was undertaken by means of mucin histochemistry, immunohistochemistry, electron microscopy and assessment of DNA microsatellite instability status. The malignant epithelium comprised well differentiated columnar cells with a microvillous brush border and expressing MUC1, but no goblet cells or expression of MUC2. The demonstration of focal clusters of intraepithelial B‐lymphocytes supported the presence of functioning M‐cells within the malignant neoplasm. The cancer was DNA microsatellite stable despite the finding of tumour infiltrating lymphocytes. Conclusions There is evidence for the origin of colorectal neoplasia from dome epithelium in both experimental models and microreconstruction studies of early adenomas in nonpolypotic human colorectal mucosa. It is suggested that the lymphocyte‐rich subset of colorectal cancer that expresses MUC1 but not MUC2 may be differentiating as dome epithelium of gut‐associated lymphoid tissue.