A Case of Ampullary Gangliocytic Paraganglioma

Gangliocytic Paraganglioma (GP) is a rare benign peculiar tumor, mostly encountered in the periampullary area of the duodenum and in the jejunum or third part of the duodenum. Duodenal GP can present as an incidental endoscopic and radiologic finding or as gastrointestinal bleeding due to uleration of the overlying mucosa. A 41-year-old female patient presented with abdominal pain. Contrast enhanced computed tomography (CT) revealed a well-defined, enhancing, 2 cm oval shaped mass at the second portion of the duodenum, adjacent to the Ampulla of Vater (AOV). Endoscopic Ultrasonography (EUS) showed a hypoechoic mass confined to the submucosal layer. Deep subepithelial forcep biopsy was done after needle knife mucosal cutting. Histologically, a relatively well-demarcated lesion was noted in the submucosal layer of the duodenum and consisted of spindle cells, ganglion-like cells, and epithelioid cells. This case showed the characteristic histologic features of a tumor composed of 3 cell types, epithelioid, spindle, and ganglion cells, which is classified as a GP. Immunohistochemical stains for S-100 protein revealed strong positive reaction in the spindle cells. The epithelioid cells and ganglion-like cells expressed synaptophysin. The immunohistochemistry results confirmed the GP diagnosis. The tumor was resected via endoscopic mucosal resection (EMR).