S6174 Nerve Matters: A Case of Duodenal Ganglioneuroma

Introduction: Duodenal ganglioneuromas are a rare, benign neoplasm. Involvement in the duodenum has been described in the literature, mainly affecting pediatric patients. Incidence in adults is exceedingly sparse with only a few case reports describing this phenomenon. This case report highlights the clinical presentation, diagnostic process, and management of a patient with duodenal ganglioneuroma. Case Description/Methods: Sixty-year-old woman with a history of ovarian cancer presented to our institution for interventional GI evaluation after a hyperattenuating lesion was discovered on computed tomography abdomen/pelvis. Prior esophagogastroduodenoscopy (EGD) performed at an outside facility investigating this area showed a subepithelial nodule in the second part of the duodenum near the ampulla. Biopsies of the surface mucosa in that area had showed benign duodenal mucosa along with findings suggestive of peptic duodenitis. Due to the subepithelial nature of the lesion, endoscopic ultrasound (EUS) was performed which showed a 13 mm hypoechoic lesion within the submucosal layer. A fine needle biopsy (FNB) was performed and pathology demonstrated neuroectodermal derived neoplasm likely representing a ganglioneuroma versus a low-grade neuroendocrine tumor. After a multidisciplinary discussion at the tumor board, the decision was made to perform endoscopic resection of this lesion. The lesion was resected enbloc with endoscopic mucosal resection (EMR). Pathology showed mature ganglion cells within a wavy stroma of spindle cells that was strongly positive for chromogranin, S100, synaptophysin and CD163 consistent with a ganglioneuroma with margins free of tumor. Patient was recommended to undergo yearly EGD/EUS for surveillance. Discussion: Duodenal ganglioneuroma is an exceedingly rare entity, with approximately 5 cases reported in adults to date. Our presentation was consistent with how these have typically manifested in previously reported cases, as slow-growing, benign and incidentally found lesions. While the exact etiology remains unclear, these tumors have been associated with genetic syndromes such as multiple endocrine neoplasia (MEN) type 2 and neurofibromatosis. However, sporadic cases, like the one presented here, are more common. This case highlights the importance of considering duodenal ganglioneuroma in the differential diagnosis of subepithelial gastrointestinal tumors. While rare, these benign tumors are treatable with endoscopic mucosal/submucosal resection, leading to excellent outcomes.