S4189 Juvenile Polyposis of the Stomach

Introduction: Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder characterized by the development of multiple hamartomatous polyps throughout the gastrointestinal tract. Diagnosis is typically based on histological examination of polyp number and location. In this case report, we present a unique case of JPS where a large gastric mass and numerous colonic polyps were initially negative for hamartomas on biopsy. Case Description/Methods: A 33-year-old woman with no prior medical history presented with worsening fatigue and was diagnosed with severe iron deficiency anemia (hemoglobin: 2.4). Physical exam revealed hyperpigmentation of the buccal mucosa (Figure 1A). Computed tomography of the abdomen and pelvis revealed diffuse thickening of the gastric and proximal duodenal wall with gastroduodenal intussusception. Colo-colonic intussusception was also noted (Figure 1B) Esophagogastroduodenoscopy identified a large nodular cystic mass protruding beyond the pylorus, involving the entire stomach (Figure 1C). Colonoscopy revealed multiple friable sessile and pedunculated polyps ranging in size from 6 to 30 millimeters in the cecum, sigmoid colon, and rectum (Figure 1D). Microscopic examination of the stomach mass revealed a hyperplastic polyp with numerous Helicobacter pylori organisms. Biopsy of the cecal polyps showed tubular adenomas while the sigmoid polyp was hyperplastic. Subsequent genetic testing revealed a SMAD4 gene mutation, confirming the diagnosis of juvenile polyposis syndrome (JPS). The patient underwent total abdominal colectomy with ileorectal anastomosis and loop ileostomy. Histological evaluation revealed juvenile polyposis throughout the resected large bowel. Due to frequent gastric outlet obstructions, surgical oncology plans to perform a total gastrectomy in the near future. Discussion: Gastrointestinal bleeding is the most prevalent initial symptom observed in JPS cases. While various forms of JPS have been described, the occurrence of massive gastric polyposis is relatively uncommon. Genetic testing should be pursued when suspicion for a polyposis syndrome is not confirmed by biopsy results, as seen in this case. Patients with a known positive family history of JPS should undergo regular upper and lower endoscopic screenings every 3 years, starting at the age of 15. Endoscopic resection of polyps should be performed until the polyp burden becomes significant enough to warrant surgical evaluation.Figure 1.: A. Buccal mucosa hyperpigmentation. B: CT A/P with diffuse thickening of the gastric and duodenal wall. C: Gastric mass. D: Colonic polyposis.