Intraductal mucin-hypersecreting neoplasm "mucinous ductal ectasia": endoscopic recognition and management

Intraductal mucin-hypersecreting neoplasm (IMHN), also termed mucinous ductal ectasia, is a rare disorder of the pancreas characterized by distension of the pancreatic duct with mucus. This study attempted to clarify the clinical, radiographic, histological, and treatment approaches to this entity.

The medical records, radiological imaging studies, and pathology specimens of eight patients with IMHN seen during a 3-yr period were reviewed. The diagnosis of IMHN was established by findings during ERCP, which included mucin plugging of the papilla, mucin extrusion from the papillary orifice after intraductal injection of contrast medium, mucinous filling defects in the main pancreatic duct, and dilated main and branch pancreatic ducts in the absence of obstructing ductal strictures.

All patients presented with an initial clinical diagnosis of acute or chronic pancreatitis, suspected cystic neoplasm, or biliary obstruction. Noninvasive imaging studies such as transabdominal ultrasonography or CT and laboratory evaluation did not seem to help in defining the disease. Five patients underwent Whipple resection; pathology included papillary ductal hyperplasia in one, dysplastic mucinous epithelium in two, and mucinous cystadenocarcinoma in two. All five patients had associated histological evidence of chronic pancreatitis. All patients are alive and well after 21-53 months without evidence of residual disease.

IMHN has a wide spectrum of clinical, radiological, and histological features. The indolent biologic behavior and favorable prognosis of IMHN suggest that it is one of the most curable forms of pancreatic malignancy.