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.

Epithelial displacement, Hamartomatous polyposis, Malignancy, Peutz-Jeghers syndrome, Pseudo- invasion, Pseudomyxoma peritonei
dx.doi.org/10.1097/00004836-199707000-00023, hdl.handle.net/1765/66750
Journal of Clinical Gastroenterology
Department of Pathology

Westerman, A.M, van Velthuysen, M.L.F, Bac, D.J, Schouten, W.R, & Wilson, J.H.P. (1997). Malignancy in Peutz-Jeghers syndrome? The pitfall of pseudo-invasion. Journal of Clinical Gastroenterology, 25(1), 387–390. doi:10.1097/00004836-199707000-00023