Gallstone ileus with transient pancreatic enzyme elevation: A case report and review of literature

BACKGROUNDCholecystoenteric fistula (CEF) is a rare complication of gallstone disease, and gallstone ileus (GI)-mechanical obstruction by an impacted stone-accounts for 1%-4% of small bowel obstructions and up to 25% of such obstructions in elderly patients.Although pancreatic enzyme abnormalities have been described in gallstone-related obstruction, marked transient hyperenzymemia can mimic primary acute pancreatitis and obscure a surgical emergency.CASE SUMMARY A 55-year-old man with a two-year history of recurrent right upper quadrant pain and known gallstones presented with a three-week exacerbation.Laboratory tests showed leukocytosis, elevated C-reactive protein, normal bilirubin, and markedly elevated lipase (8175 U/L) and amylase (2104 U/L) that decreased to 209 U/L and 137 U/L, respectively, within 24 hours.Computed tomography showed pericholecystic fluid, pneumobilia, small-bowel air-fluid levels, and a calcified rim sign.After five days of unsuccessful conservative treatment, surgery revealed an impacted gallstone approximately 100 cm from the ligament of Treitz with segmental bowel ischemia; three stones were extracted via enterolithotomy, and the ischemic segment was resected.Interval laparoscopic cholecystectomy with repair of the cholecystoduodenal fistula was performed six months later, and the patient was asymptomatic at one-year follow-up. CONCLUSIONMarked transient pancreatic enzyme elevation without computed tomography signs of pancreatitis, which does not exclude a mild concurrent pancreatitis, is a diagnostic pitfall that may mimic acute pancreatitis and obscure a mechanical obstruction; when such enzyme kinetics coexist with pneumobilia or an ectopic gallstone, the differential 4 / 24 diagnosis may be broadened toward CEF with GI, and early surgical consultation may be warranted.