Pancreatic Cyst: Pseudocyst or Neoplasm? Pitfalls in Endoscopic Retrograde Cholangiopancreatography Diagnosis

Abstract

Pancreatic pseudocysts represent the majority of cystic lesions, and can usually be differentiated from cystic neoplasms, which have malignant potential. Endoscopic retrograde cholangiopancreatography (ERCP) can help in solving diagnostic dilemmas. When ERCP demonstrates cyst communication with the pancreatic duct, the diagnosis of pseudocyst is usually secure. There are exceptions, however, as reported in these two case reports. A retrospective chart review was conducted of two patients undergoing distal pancreatectomy in 2008 to 2009 for cystic lesions communicating with the main pancreatic duct on ERCP. Both patients were women (ages 37 and 42) with a history of chronic abdominal pain and pancreatitis. Radiologic imaging showed cystic lesions in the pancreatic tail. ERCP demonstrated main pancreatic duct communication. When endoscopic management failed, surgical therapy was undertaken. Both patients underwent distal pancreatectomy with splenectomy. Pathologic findings were mucinous cystadenoma. The conventional wisdom that a pancreatic cyst communicating with the main pancreatic duct is a benign pseudocyst is not always wise. As seen in this series, mucinous cystadenomas can erode into the main pancreatic duct. Women in the fourth and fifth decade with symptomatic cysts in the pancreatic tail with a history of pancreatitis should undergo distal pancreatectomy, regardless of ductal communication on ERCP.