This case describes a 35-year-old male with a subhepatic gallbladder—an uncommon congenital anomaly—presenting with acute calculous cholecystitis and choledocholithiasis. Anatomical variations of the gallbladder are relatively frequent; however, positional anomalies such as subhepatic or ectopic gallbladders are rare, with an incidence of less than 1%. They are often discovered incidentally during imaging or surgery because clinical symptoms mimic typical biliary colic [4–6].

In our patient, preoperative MRCP accurately identified the subhepatic location, which allowed for careful operative planning. Most previously reported cases describe the anomaly being detected intraoperatively, increasing the risk of iatrogenic injury.

Awareness of gallbladder positional variations is crucial for surgeons to prevent bile duct injury, particularly during laparoscopic cholecystectomy where altered anatomy increases the risk of iatrogenic complications. Anomalies such as subhepatic, intrahepatic, or left-sided gallbladders are uncommon but clinically significant, as they can alter the expected orientation of Calot’s triangle and biliary structures, making dissection technically demanding [6, 7]. Failure to recognize these variations preoperatively may lead to misidentification of biliary anatomy and subsequent bile duct injury or conversion to open surgery [8].

From an embryological perspective, positional anomalies of the gallbladder are thought to result from abnormal migration of the hepatic diverticulum during early fetal development. The gallbladder and bile ducts originate from the caudal portion of the hepatic diverticulum, and failure of proper rotation or migration can result in ectopic positioning such as subhepatic, intrahepatic, retrohepatic, or even left-sided locations. Understanding these developmental mechanisms not only aids in interpreting unusual imaging findings but also reinforces the importance of anatomical awareness during hepatobiliary surgery.

Preoperative imaging plays a pivotal role in diagnosis. When the gallbladder is not visualized in its usual fossa on ultrasonography, further evaluation with MRCP is recommended to delineate the biliary anatomy and detect associated anomalies [9, 10]. MRCP provides a noninvasive, detailed assessment of the biliary and pancreatic ducts, allowing better surgical planning and risk reduction [11, 12].

Intraoperatively, meticulous dissection and the application of the “critical view of safety” technique are essential when dealing with atypical gallbladder anatomy. Surgeons should identify only two structures entering the gallbladder—the cystic duct and cystic artery—before transection. When visualization of Calot’s triangle is unclear, adjuncts such as intraoperative cholangiography, indocyanine green fluorescence imaging, or conversion to open cholecystectomy may be warranted to minimize the risk of bile duct injury. A methodical and patient approach, combined with preoperative imaging, significantly reduces intraoperative uncertainty and enhances patient safety.

Although our patient experienced a favorable postoperative recovery, continued long-term follow-up remains essential to identify delayed biliary complications such as stricture formation, retained stones, or stent-related issues.

This case reinforces the importance of maintaining a high index of suspicion for positional gallbladder anomalies, careful preoperative assessment, and intraoperative vigilance to ensure patient safety and optimal outcomes [13].