Inflammatory pseudotumour arising from periampullary carcinoid: a "cancer-like" tumour in a "fake" tumour.

Carcinoid tumours of the gastrointestinal tract are uncommon, generally slow-growing and associated with a good prognosis. We present a 52-year-old Chinese woman with a carcinoid at the ampulla of Vater, a site far less common than other areas of the gastrointestinal tract. Preoperative imaging showed a pancreatic mass with displacement and possible invasion of the portal vein associated with peripancreatic nodal enlargement. A radical pancreaticoduodenectomy with portal vein wedge excision was performed. An intraoperative biopsy of the enlarged nodes was negative for malignancy and postoperative histology of the large pancreatic mass yielded a surprising finding of a carcinoid tumour at the ampulla of Vater with a large inflammatory pancreatic mass adherent to the portal vein. This is an uncommon case associated with "pseudotumour pancreatitis", causing biliary and pancreatic duct obstruction mimicking a large tumour in the head of the pancreas.