Fish-mouth appearance of the ampulla of Vater.

Cystic tumors of the pancreas account for less than 10% of pancreatic neoplasms. Intraductal papillary mucinous carcinomas (IPMNs) account for 21-33% of these tumors. IPMNs represent papillary neoplasms within the main pancreatic duct and/or side branches showing mucin hypersecretion that often leads to duct dilation and chronic obstructive pancreatitis [1].

A 55-year-old patient presented with a history of epigastric pain beginning 5 years ago. During this period the patient had experienced an episode of acute pancreatitis, shortly after which a computed tomography (CT) of the abdomen revealed a pancreatic pseudocyst.

An upper endoscopy using a side view endoscope was performed, revealing a patulous ampulla of Vater with extruding mucus (Fig. 1), the fish-mouth sign, practically pathognomonic for an IPMN.

Figure 1

(A) Endoscopic appearance of the ampulla of Vater, showing the fish-mouth sign (B) The ampulla of Vater is shown, extruding mucus

IMPNs represent potentially malignant lesions, occurring equally in both genders. Abdominal pain and weight loss are the most common complaints. A history of recurrent pancreatitis is given by 20% of patients, and acute pancreatitis is found in 25% at presentation. Evaluation involves CT or MRI of the abdomen, endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS). Typically, dilation of the pancreatic duct with or without an associated cystic mass is demonstrated. EUS with FNA (fine needle aspiration) provides important information such as the degree of dysplasia, cell-type, extent of disease and malignant potential. Treatment of IPMNs frequently requires pancreatic B resection, which successfully relieves symptoms and prevents progression to invasive carcinoma. Prognosis after resection of IPMN is excellent, with five-year disease specific survival of 75% or better [2,3].