title: Epithelial misplacement in Peutz-Jeghers polyps. A diagnostic pitfall.
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.
authors: Department of Pathology, St. Mark's Hospital, London, England.
authors: N A
authors: NA
authors: Shepherd
authors: H J
authors: HJ
authors: Bussey
authors: J R
authors: JR
authors: Jass
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D003937:Diagnosis, Differential; D004848:Epithelium / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007417:Intestinal Polyps / Q000175:diagnosis / Q000473:pathology*; D010580:Peutz-Jeghers Syndrome / Q000473:pathology*; D011127:Polyps / Q000175:diagnosis / Q000473:pathology*; D013274:Stomach Neoplasms / Q000473:pathology*