Rare solitary giant hamartomatous polyp of the stomach removed by endoscopic submucosal dissection

The incidence of solitary gastric hamartomatous polyps (SGHPs) is extremely low, with fewer than 12 cases reported in the literature. Common symptoms include abdominal pain, bleeding, and anemia. While most SGHPs are benign, dysplastic changes have been reported.^, Hence, large lesions are typically referred for resection. In this video, we present a case of an SGHP resected with endoscopic submucosal dissection (ESD) (Video 1, available online at www.giejournal.org).

A 73-year-old man with medical history significant for atrial fibrillation on antithrombotic therapy and congestive heart failure was evaluated for weight loss and iron deficiency anemia. He underwent an EGD, video capsule endoscopy, colonoscopy, and CT scan of the abdomen/pelvis. All tests were unremarkable except for a large gastric mass identified on the EGD, with forceps biopsy histopathology suggestive of a hyperplastic polyp. The patient was referred to our institution for possible resection. On EGD, a large sessile, lobulated polyp with a convoluted surface (Paris classification Is+IIc) was located on the posterior wall and greater curvature of the stomach (Fig. 1). Mucosal surface of the lesion was smooth without ulceration and high-definition white light and narrow-band imaging did not show microvascular morphology suggestive of deep invasion. Given the patient’s symptoms and consideration for a malignant component because of the size of the lesion, the decision was to proceed with ESD. Cautery marks were placed along the outer margins of the lesion. A lifting solution (6% hetastarch admixed with methylene blue) was injected into the submucosa at the anal aspect of the target lesion followed by mucosal incision using a needle-injection electrosurgical knife (Hybrid I-type knife; ERBE, Marietta, Ga, USA) (Fig. 2A). Following this, ESD was completed using the submucosal tunneling technique as previously described. In brief, a mucosal incision was performed on the oral side followed by submucosal dissection by creating a tunnel underneath the lesion (Fig. 2B). Upon completion of the submucosal tunnel, the lateral mucosal margins were excised and dissected (Fig. 2C). There was no evidence of bleeding or perforation at the conclusion of the procedure (Fig. 3). Total procedure time was 147 minutes. The resected specimen (170 × 72 mm) was retrieved en bloc, mounted onto a cork board, and fixed in formalin (Fig. 3). The patient developed acute onset of abdominal pain on postoperative day 1. A CT scan revealed pneumoperitoneum and fluid collection on the greater curvature of the stomach consistent with delayed perforation (Fig. 4). Surgery was consulted who agreed with endoscopic intervention. While definitive perforation was not identified on repeat EGD, based on clinical presentation and CT findings, we proceeded with endoscopic closure of the entire resection bed, which was successfully achieved by placing 4 interrupted sutures in a “Z” pattern with the endoscopic suturing system (Overstitch; Apollo Endosurgery, Austin, Tex, USA) (Fig. 5). Following this, a CT-guided percutaneous drain was placed for the small fluid collection. An upper GI series showed no evidence of contrast extravasation, and the patient was able to advance his diet (Fig. 6). The drain was removed, and patient was discharged on postoperative day 7. He completed a 14-day course of amoxicillin-clavulanate 875-125 mg and was doing well 4 weeks postprocedure.

Final histopathology was consistent with a benign gastric hamartomatous polyp (Fig. 7). The patient reported no family history of GI polyposis, associated mucocutaneous pigmentations, nor other polyps in the GI tract, consistent with the diagnosis of an SGHP. Because of its rarity, there are no clear guidelines in the management of SGHPs. Superficial forceps biopsies are often misdiagnosed as hyperplastic. SGHPs have a highly vascular stroma, which explains their tendency to bleed. Given the reported risk for neoplastic transformation, SGHPs are generally referred for resection.^, ESD may be an alternative to surgery for selected cases. We recommend close postoperative monitoring as delayed perforation can occur after large resections, and prompt recognition and intervention can prevent peritonitis and need for surgery. Our case is the largest SGHP reported that has been removed endoscopically.