These are biopsies from an woman with multiple gastric polyps. The flat mucosa was edematous but normal. Based on the histologic findings, a SMAD4/DPC4 stain was added. What is your diagnosis?
Answer: This is an incredible example of presumed gastric juvenile polyposis.
Comment: There is SMAD4/DPC4 loss in the areas of dysplasia in the polyps. This loss suggests that the patient has a germline mutation in the gene, a loss that can be associated with juvenile polyposis restricted the stomach. When there is dysplasia, it can show several patterns of differentiation in these patients, as discussed by Dr. Cathy Ma in 2014. In general, gastric syndromic polyps can be very difficult to classify, as outlined in the references below.
This case is provided by Dr. Elizabeth Montgomery, the Editor-in-Chief of the Pathology Survival Guides at Innovative Science Press, and a professor of pathology and Vice Chair of Anatomic Pathology at the University of Miami. Her book Survival Guide to GI Biopsies will soon be out of stock. Order your copy at: