[Diagnostic value of aspiration cytology with ERCP]

ERCP is of great value in diagnosing malignant pathology of the biliopancreatic duct system. However, the ERCP endoscopic characteristics in malignant stenosis often lack specificity and are difficult to differentiate from those of chronic pancreatitis. In these cases histological confirmation is essential to diagnosis. With the aim of increasing the diagnostic possibilities of ERCP in pancreatic cancer--particularly when associated with chronic pancreatitis--we performed aspiration cytology of pancreatic juice obtained via endoscopic cannulation of the main pancreatic duct using ERCP in 102 patients with suspected periampullar pathology, chronic pancreatitis and/or pancreatic cancer. The diagnostic sensitivity of cytology for pancreatic malignancy was 33.3%, versus 60% for cancer of Vater's papilla. Specificity was 100% in both cancers. We observed no false positive results or complications. On combining both techniques, i.e., ERCP and cytology of the pancreatic juice, sensitivity increased to 100% for pancreatic malignancy, 77.7% for chronic pancreatitis (characteristic ERCP radiographic images and absence of neoplastic cells) and 100% in the case of ampullomas. Difficulties in the differential diagnosis between advanced chronic pancreatitis and pancreatic cancer persist with ERCP alone. In such cases aspiration cytology may secure a definitive diagnosis--particularly when neoplastic cells are demonstrated (Class IV).