Entertis Cystica Profunda in Puetz-Jeghers Syndrome (PJS): A Case of Pseudo-Invasion

Abstract

Purpose: 20-year-old Caucasian female with PJS with documented STK 11 mosaic mutation, underwent a wireless capsule study to evaluate abdominal pain. The capsule showed a large ileal polyp (Figure 1), biopsy of which showed a hamartoma without dysplasia, consistent with PJS. Attempts to remove the polyp endoscopically was unsuccessful due to its broad base. Patient later underwent a small bowel resection removal of 10 cm of her ileum along with the indurated broad based polyp which measured 1.5 x 1.0 cm. The pathology report determined the polyp to be a benign mucin filled cysts in the bowel wall penetrating through the mucosal layer consistent with enteritis cystica profunda (ECF). ECF are thought to arise after mucosal ulceration or inflammatory damage to the submucosa which allows outgrowth of epithelial element into other layers of the bowel wall. The histological findings of these mucin filled cysts leading the “ pseudoinvasion” (Figure 2) of the epithelial glands extending into the muscularis propia and serosa have been confused for mucin producing adenocarcinomas. Although there is an increased risk of malignant transformation in PJS, when surgical resection is required, a limited resection is recommend to minimize bowel loss. PJS polyps with epithelial misplacement can be confused with invasive cancer but the lack of nuclear atypia, normal appearing small bowel cells and lack of lymphatic invasion all serve to support the hamartomatous origin of a benign PJS polyp. Recognition of pseudo-invasion or enteritis cystica profunda of PJS polyps will prevent unnecessary surgical bowel resections.Figure: Endoscopic view of polyp.Figure: Pseudo-invasion of a Puetz-Jeghers polyp.