Laparoscopic Cholecystectomy Mirizzi Syndrome Due to a Long Dilated Cystic Duct Stump as a Result of an Impacted Stone: A Diagnostic and Surgical Pitfall.

Mirizzi syndrome (MS) is an uncommon complication of gallstone disease in which an impacted stone in the cystic duct or gallbladder neck leads to external compression of the common bile duct (CBD). Its clinical and imaging features often mimic other hepatobiliary conditions, making preoperative diagnosis challenging and increasing the risk of biliary injury. We report the case of a 34-year-old male who presented with sudden-onset right upper quadrant pain. His history of gallstones and examination findings suggested acute calculous cholecystitis. Laboratory tests revealed elevated liver enzymes, while abdominal ultrasound demonstrated gallstones without CBD dilation. He underwent a laparoscopic cholecystectomy on hospital day three. Intraoperative findings included a distended gallbladder with a dilated cystic duct and CBD. Postoperative magnetic resonance cholangiopancreatography (MRCP) revealed a long cystic duct stump with an impacted stone causing compression of the CBD and proximal biliary dilation, consistent with MS. Subsequent endoscopic retrograde cholangiopancreatography (ERCP) confirmed the diagnosis, and sphincterotomy with CBD stenting was performed. The patient recovered uneventfully and remained stable on follow-up. This case underscores the importance of maintaining a high index of suspicion for MS, particularly in patients with gallstones presenting with atypical features or persistent biliary dilation. Early identification and multidisciplinary management are crucial for preventing complications and ensuring optimal outcomes.