Possible congenital dilatation of the pancreatic duct.

The main pancreatic duct can become dilated in a number of conditions. We describe a patient with gross dilatation of the main pancreatic duct without evidence of causative underlying pathology suggesting congenital dilatation of the pancreatic duct. A 36-year-old man presented with signs of intestinal obstruction and a history of surgery for congenital pyloric stenosis. Incidental findings on CT showed a massively dilated main pancreatic duct. On MRI there was no duct irregularity or solid mural nodule, making a main duct intraductal papillary mucinous neoplasm unlikely. Endoscopic ultrasound findings were in keeping with those on MRI. Fine needle aspiration revealed a non-viscous fluid with a low carcinoembryonic antigen and high amylase concentration, consistent with normal pancreatic fluid levels rather than a mucinous collection. After 1 year, the cyst remains unchanged. This patient will be kept under surveillance with yearly MRI.