S6016 Endoscopic Resection of an Incidental Gangliocytic Paraganglioma Complicated by Delayed Bleeding: Lessons in Procedural Planning

Introduction: Gangliocytic paraganglioma (GP) is a rare neuroendocrine tumor typically located in the duodenum. While frequently asymptomatic, it may present with abdominal pain and gastrointestinal (GI) hemorrhage. Due to its resemblance to other GI malignancies, biopsy is required for diagnosis. Here, we present a case of an incidental gangliocytic paraganglioma removed endoscopically and complicated by delayed post-polypectomy bleeding. Case Description/Methods: A 60-year-old man with coronary artery disease (stents placed 2 years prior, on dual antiplatelet, aspirin and plavix, therapy (DAPT)), thyroid cancer with hemithyroidectomy and Parkinson's disease presented with dysphagia and abdominal pain for 1 year. His labs and computed tomography abdomen/pelvis were normal. Esophagogastroduodenoscopy (EGD) found an atypical pedunculated submucosal mass in the second part of the duodenum with normal overlying mucosa. Endoscopic ultrasound (EUS) noted a 17.2 × 14.1 mm heterogenous, isoechoic mass with a hypoechoic nodularity at its apex and small feeding vessel on doppler. This mass was completely resected by hot snare polypectomy and 2 hemoclips were placed for hemostasis. Plavix was held for 7 days prior to the procedure. On pathology, immunohistochemical stain was positive for AE1/AE3, S100 protein, chromogranin, and synaptophysin and negative for CD117, confirming gangliocytic paraganglioma. He presented 5 days post-polypectomy with melena and symptomatic anemia (Hgb 13.5 to 8.8 g/dL, baseline 15 g/dL) after resuming DAPT 1-day post-procedure. EGD noted bleeding at the polypectomy site that was controlled with epinephrine, bipolar cautery, and a hemoclip. DAPT was de-escalated to aspirin only. One year later, EGD and EUS found no residual tumor or evidence of lymphadenopathy. Discussion: GPs are characterized by 3 histologic cell types: epithelioid (AE1/AE3), schwannian (S100), and ganglion (chromogranin or synaptophysin). Accurate diagnosis is essential to avoid misdiagnosis of more aggressive malignancies, such as GI stromal tumors or metastases. Endoscopic or surgical management depends on tumor size, location, and lymph node involvement. Few post-polypectomy bleeding for GPs, potentially from prominent feeding vessels, have been reported; however, no prior post-polypectomy cases that the authors could identify involved DAPT. This case highlights the need for careful planning and monitoring to minimize complications when approaching resection of atypical masses for patients on DAPT or anticoagulation.