Original Articles: PDF OnlyEpithelial Misplacement in Peutz-Jeghers Polyps A Diagnostic PitfallShepherd, N A M.B., B.S., M.R.C.Path1; Bussey, H J R B.Sc., Ph.D.2; Jass, J R B.Sc., M.D., M.R.C.Path3Author Information 1From the Department of Pathology and ICRF Colorectal Cancer Unit St. Mark's Hospital, City Road, London and the Department of Histopathology St. Bartholomew's Hospital, West Smithfield, London, England. 2From the Department of Pathology St. Bartholomew's Hospital, West Smithfield, London, England. 3From the Department of Pathology and the Department of Histopathology St. Bartholomew's Hospital, West Smithfield, London, England. The American Journal of Surgical Pathology: October 1987 - Volume 11 - Issue 10 - p 743-749 Buy Abstract Early difficulties with the interpretation of the histopathology caused overdiagnosis of cancer in the Peutz- Jeghers syndrome; and there is still controversy about the magnitude of risk of gastrointestinal carcinoma. Most workers now believe that there is a small but definite increase in the incidence of gastrointestinal carcinoma in Peutz-Jeghers polyps and most of these cancers occur in the upper gastrointestinal tract. In a review of 491 Peutz- Jeghers polyps in the records of St. Mark's Hospital Pathology department, misplacement of epithelium was found in approximately 10% of small intestinal polyps and closely mimicked adenocarcinoma. This “pseudoinvasion” was not observed in polyps of the stomach or colon. The epithelial misplacement may involve all layers of the bowel wall; and the most helpful histological discriminators include a lack of cytological atypia, the presence of the normal epithelial cell subtypes and a brush border, hemosiderin deposition, and intramural mucinous cysts. Epithelial misplacement may account for the overdiagnosis of carcinoma arising in Peutz-Jeghers polyps as reported in the literature. © Lippincott-Raven Publishers.