HPB SO17 - A rare case of Goblet cell adenocarcinoma of appendix presenting as primary ampullary tumour

Abstract Background Goblet cell adenocarcinoma (GCA), formerly known as goblet cell carcinoid,is a rare appendiceal tumour with amphicrine differentiation that has distinct morphologic and clinical features compared to carcinomas seen elsewhere in the gastrointestinal tract. The tumour histologically resembles both carcinoids and adenocarcinomas. It is found in 0.3–0.9 % of appendectomy specimens; hence, ampullary GCAs are exceptionally uncommon. Method A 57-year-old Caucasian male presented with a two-month history of weight loss, pruritus, and dark urine. His blood tests revealed deranged liver enzymes. His past medical history was unremarkable. Abdominal CT identified a double duct sign, no detectable mass. Endoscopic ultrasound (EUS) revealed a dilated biliary system terminating in a slightly enlarged ampulla (15mm) without any obvious mass lesions. Endoscopic retrograde cholangiopancreatography (ERCP) was performed showing a distal common bile duct (CBD) stricture. Cytology samples were negative for malignancy, and stents were placed in the CBD and pancreatic duct (PD). Pancreaticoduodenectomy was advised given the high risk of malignancy. Results Histopathology report showed clusters of goblet-like mucinous cells in an infiltrative pattern, in addition to classic neuroendocrine tumor morphology, reminiscent of goblet cell adenocarcinoma of the appendix, staged as pT3pN1M0. This is consistent with primary ampullary GCA given the normal appendix on preoprative CT imaging. Conclusion To our knowledge, this is the fourth case of ampullary GCA report in medical literature. There is no consensus on adjunct chemotherapy regimen for systemic treatment. Chicago consensus group (2018) recommends following the colorectal cancer pathway for goblet cell adenocarcinoma. In our experience, given the anatomical location of the tumour and the normal appendix, FOLFIRINOX was offered in line with ampullary adenocarcinoma cancer pathway.