MALIGNANCY IN PEUTZ-JEGHERS-SYNDROME - THE PITFALL OF PSEUDO-INVASION

Peutz-Jeghers syndrome is a malignancy-associated polyposis syndrome. We describe a histopathologic phenomenon easily encountered when exami ning the nature of Peutz-Jeghers polyps but that is underreported in t he literature. This phenomenon of ''pseudo-invasion'' may mimic invasi ve carcinoma due to epithelial displacement and erroneously give the i mpression, both macroscopically and microscopically, that a malignancy is involved. This potential pitfall is illustrated by the case of a p atient with Peutz-Jeghers syndrome who was thought to harbor a metasta sizing adenocarcinoma in his small bowel with peritoneal metastasis as a perioperative finding. Histologic examination, however, revealed ps eudo-invasion.