title: Malignancy in Peutz-Jeghers syndrome? The pitfall of pseudo-invasion.
abstract: Peutz-Jeghers syndrome is a malignancy-associated polyposis syndrome. We describe a histopathologic phenomenon easily encountered when examining the nature of Peutz-Jeghers polyps but that is underreported in the literature. This phenomenon of "pseudo-invasion" may mimic invasive carcinoma due to epithelial displacement and erroneously give the impression, both macroscopically and microscopically, that a malignancy is involved. This potential pitfall is illustrated by the case of a patient with Peutz-Jeghers syndrome who was thought to harbor a metastasizing adenocarcinoma in his small bowel with peritoneal metastasis as a perioperative finding. Histologic examination, however, revealed pseudo-invasion.
authors.affiliation: Department of Internal Medicine, Erasmus University, Rotterdam, The Netherlands.
authors.forename: A M
authors.initials: AM
authors.lastname: Westerman
authors.forename: M L
authors.initials: ML
authors.lastname: van Velthuysen
authors.forename: D J
authors.initials: DJ
authors.lastname: Bac
authors.forename: W R
authors.initials: WR
authors.lastname: Schouten
authors.forename: J H
authors.initials: JH
authors.lastname: Wilson
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology*; D010375:Pedigree; D010580:Peutz-Jeghers Syndrome / Q000473:pathology*