Massive pancreatic pleural effusion: pathogenesis of pancreatic duct disruption.

Massive pancreatic pleural effusion is believed to be caused by pancreatic duct disruption. To elucidate the cause of the duct disruption, pancreas specimens resected from three cases of massive pancreatic pleural effusion were investigated histopathologically. There was no evidence of either chronic or acute pancreatitis except focal fibrosis along a single dilated duct in the resected pancreas. From our study, the pathogenesis of pancreatic duct disruption is suggested as follows: (a) alcohol ingestion can induce focal acute inflammation on a single branch of the duct system and elicit protein plug formation; and (b) focal stenotic change occurs on this branch at a point near the main pancreatic duct, and transient obstruction can occur by means of the protein plugs. The "upstream" extent of this branch will then dilate until it ruptures. However, on the frequency of this atypical pancreatitis, we have no clues to mention.