A 67-year-old man presented with a 12-month history of epigastric discomfort and low normal iron stores for at least 3 years (ferritin 32-42ug/L), but no weight loss. He had a history of hypertension, hypercholesterolaemia and chronic obstructive pulmonary disease. Gastroscopy revealed a large ampullary polypoid mass without bleeding, and endoscopic ultrasound demonstrated a submucosal lesion 30x12mm in the ampullary/periampullary region. Cytology revealed a malignant cell pattern of unclear differentiation. Staging FDG-PET scan revealed intense uptake in the periampullary mass, with uptake in pulmonary hilar/mediastinal lymph nodes and caecum, though no mass lesions were present on colonoscopy. Staging laparoscopy revealed no peritoneal disease, and a Whipple’s pancreatoduodenectomy with cholecystectomy was performed. Histopathology revealed a well-differentiated ampullary gangliocytic paraganglioma (GP) with clear margins and no lymph node involvement. There was no loss of staining for SDHB, SDHA and fumarate hydratase.
Duodenal GPs are rare tumours with only 236 cases reported between 1957 and 2018 (1). They are reported in people aged 16 to 92 years with a male predominance (1.8:1) (2,3). Ninety percent arise from the second part of the duodenum (4). Whilst frequently asymptomatic, common presenting symptoms include abdominal pain and melaena (4,5). Histologically, GPs consist of 3 cell types: spindle, epithelial and ganglion (5). They can be misdiagnosed as Grade 1 neuroendocrine tumors (NET) (6). However, accurate diagnosis is important, as GPs have a better prognosis than NETs and other ampullary tumours (4,6). Nonetheless, though generally considered benign, distant metastasis and rarely, death have been reported (1,7). Optimal treatment remains unclear due to low case numbers, but includes options of endoscopic resection or surgical resection +/- adjuvant radiotherapy (3,8). Recurrence post-resection is rare but has been reported up to 11 years post-operatively (5). Follow up is imperative as no prognostic biomarkers are available (9,10).