Pancreatic pseudocyst caused by extracorporeal shock wave lithotripsy for right renal pelvic calculi.

A 39-year-old white man with a history of right renal pelvic stones treated 1 year before by extracorporeal shock wave lithotripsy, but with no history of major surgery, alcoholism, pancreatitis, hyperparathyroidism or trauma, was admitted, suffering from an abdominal mass. Abdominal and pelvic computed tomography revealed an enlarged pancreatic head (9 cm in transverse diameter) with, inside it, a heterogeneous, cyst-like structure, measuring 7 cm in diameter. It was suspected that this lesion was a cystic neoplasm and the patient underwent a proximal pancreaticoduodenectomy and a cholecystectomy. After the operation, the microscopic findings ruled out the presence of a neoplasm and we were obliged to reconsider the case. Speculating as to the possible role of past extracorporeal shock wave lithotripsy in determining the pancreatic pseudocyst, it was found that damage to the intra-abdominal organs during extracorporeal shock wave lithotripsy has been mentioned in published series, but it was also noted that this case seemed to differ from the other published cases, where cirrhosis and thrombocytopenia, gallbladder stones, or adhesions between the pancreas and surrounding tissue caused by laparotomy were considered the causes of the lithotripsy complications. We suggest a direct traumatic disruption of the pancreas as a result of the extracorporeal shock wave lithotripsy and conclude that the post-lithotripsy follow-up should include periodic ultrasonographic investigation of the pancreas and serum amylase level determinations in order to diagnose pancreatic complications, if any, and plan the correct treatment.