title: Tubular adenoma with focal squamous metaplasia of the ascending colon.
abstract: A case of tubular adenoma with focal squamous metaplasia of the ascending colon in a 66-year-old male is reported. The tumor was a pedunculated polyp with a size of 1.5 X 1.4 X 0.9 cm. Histologically, the tumor showed tubular adenoma with moderate to severe atypia, was accompanied by focal squamous metaplasia. It is thought that squamous epithelial polyp may be derived from colonic adenoma with squamous metaplasia, and that the malignant change of colonic adenoma with squamous metaplasia may lead to squamous cell carcinoma, adenosquamous carcinoma, and mucoepidermoid carcinoma. Only seven cases of colonic adenoma with squamous metaplasia have been reported previously in the literature, and it is yet necessary to discuss the histogenesis, significance, and natural history of colonic adenoma with squamous metaplasia.
mesh_terms: D000368:Aged; D003106:Colon / Q000473:pathology; D003111:Colonic Polyps / Q000473:pathology*; D006801:Humans; D008297:Male; D008679:Metaplasia