title: Pseudomalignant ulcerative change of the gastrointestinal tract.
abstract: The occurrence of pseudomalignant ulcerative change in seven specimens from the colon and rectum of six patients is described. In all cases, there was surface ulceration of a polypoid lesion which contained granulation tissue and acute and chronic inflammation. There was an underlying inflammatory pseudopolyp in four lesions, a juvenile polyp in one lesion, an adenomatous polyp in one lesion, and a benign retention polyp in one lesion. Within the stroma of all cases were numerous atypical cells that mimicked a malignant neoplasm. The atypical cells expressed vimentin in immunohistochemical studies; no expression of keratins, leukocyte common antigen, factor VIII, Ulex europaeus, carcinoembryonic antigen, actin, or desmin was found. Recognition of this lesion is important, as confusion with carcinoma, lymphoma, sarcoma, or a viral infection may easily occur.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, CA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Berry
authors.forename: W C
authors.initials: WC
authors.lastname: Pitts
authors.forename: L M
authors.initials: LM
authors.lastname: Weiss
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003093:Colitis, Ulcerative / Q000150:complications / Q000473:pathology; D003110:Colonic Neoplasms / Q000150:complications / Q000473:pathology*; D003111:Colonic Polyps / Q000150:complications / Q000473:pathology; D003424:Crohn Disease / Q000150:complications / Q000473:pathology; D006801:Humans; D007417:Intestinal Polyps / Q000150:complications / Q000473:pathology*; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000150:complications / Q000473:pathology*; D012811:Sigmoid Neoplasms / Q000150:complications / Q000473:pathology; D014456:Ulcer / Q000473:pathology