Gastric Hamartomatous Inverted Polyp Causing Ball Valve Syndrome

Abstract

A 75-year-old woman with no significant past medical history presented for worsening fatigue and postprandial nausea. Laboratory data showed a hemoglobin level of 2.4 g/dL. Esophagogastroduodenoscopy showed that a pedunculated polyp arising from the lesser curvature of the upper gastric body was intussuscepted into a pylorus ring (Figure A). The polyp was pulled back into the stomach with grasping forceps. A mucinous fluid was secreting from the polyp, and dilated vessels were observed on its surface (Figure B). Endoscopic ultrasonography showed a heterogeneous lesion in the third layer of the gastric wall with variable cystic components (Figure C). For a definitive diagnosis and treatment of this polyp, the patient underwent endoscopic submucosal dissection (ESD). Histopathology showed submucosal proliferation of pseudo-pylorus glands, cystic glands, and smooth muscle bundles with no atypia (Figure D), thus confirming a diagnosis of a gastric hamartomatous inverted polyp (GHIP). Her symptoms disappeared and anemia improved after ESD. GHIP is rare, and most GHIPs are detected incidentally. Interestingly, in the present case, GHIP caused ball valve syndrome. Considering her clinical improvement after ESD, the main reason for her anemia could have been related to a mechanical disruption of the dilated veins on the polyp surface by ball valve syndrome. The authors would like to thank Editage (www.editage.jp) for English language editing.