Mucinous cystic neoplasms of the pancreas.

Mucinous cystic neoplasms of the pancreas (MCNP) are rare tumors with presentation and findings that differ in most cases from pancreatic pseudocysts. A simple pancreatic cystic lesion in a younger-aged patient with a history of pancreatitis and endoscopic retrograde cholangiopancreatography (ERCP) demonstration of ductal communication with the cyst strongly suggests the diagnosis of a benign pseudocyst. MCNP may have extensive areas without an epithelial lining, adding histologic sampling error to the potential for confusing these two entities. Pancreatic pseudocysts are benign lesions treated by enteric drainage procedures, while MCNP have significant malignant potential, and resection is advised. Even when clinical presentation and imaging are persuasive for a benign cyst, MCNP of the pancreas should be considered in planning, evaluation, and treatment.