atypical localization of the gallbladder ( gb ) , as a rare anomaly of the biliary system , is defined as a gb located to the left side of the ligamentum teres ( lt ) without situs inversus viscerum . because of its localization just to the left of lt , it was usually misnamed as only a left - sided gallbladder ( lsgb ) without detailed anatomic examination which gives exact pathology causing this anomaly . an association with anomalies of the biliary and portal venous systems is an important issue especially during laparoscopic cholecystectomy and hepatectomy , particularly with living donor transplantation . in this report , we aim to present an atypical localization of gb related to rslt treated by standard laparoscopic cholecystectomy , and its detailed anatomic topography . a 31-year - old female patient was admitted to the surgical clinic because of recurrent right upper quadrant pain during the last 2 months . she was taken into the operating theatre with a diagnosis of cholelithiasis . at exploration , the gb was absent from its normal location , and it was found just left to lt [ figure 1 ] . it had edematous and hydropic appearance with an impaction of a calculus at the neck . with the standard localization of ports and a lt lift , it was possible to perform cholecystectomy via laparoscopically in a retrograde manner . during the operation , it was found that there was a short and wide cystic duct joining to the common bile duct on the right side , and the cystic artery with anterior and posterior branches originating normally from the right hepatic artery . intraoperative demonstration of the gallbladder located to the left side of the ligamentum teres magnetic resonance cholangiopancreatography and angiography were performed to understand the biliary and portal venous system anomalies . this showed the first branch of the portal vein ( pv ) running to the right posterior segment , and then formation of the main trunk of the left and right anterior pvs [ figure 2 ] . the latter vein formed saccularly dilated umbilical portion of pv and finally joined to lt [ figure 3 ] . main portal vein gives off the right posterior portal vein as the first branch ( thin white arrow ) , and then continue with formation of the main trunk of the left and right anterior portal veins ( thick white arrow ) contrast - enhanced axial t1w magnetic resonance image of the liver at the level of the ligamentum teres shows that saccularly dilated umbilical portion of the right anterior portal vein ( thin white arrow ) finally joins to the ligamentum teres ( thick white arrow ) in the absence of situs inversus , atypical localization of gb is a rare anomaly of the biliary system , which was reported firstly by hochstetter in 1886 . in the literature , this anomaly was reported , mostly from japan , with an incidence of 0.1 - 1.2 % . with advance of imaging techniques , atypical localization of gb associated with or without rslt , usually accompanied by abnormal intrahepatic portal venous branching is increasingly reported . it is accepted that for a diagnosis of lsgb , it must be located not only to the left of lt , but also under the surface of the left liver where the main middle hepatic vein clearly runs to the right of gb , and lt itself should be originated from the left pv . during embryologic development , with the atrophy of rslt in some individuals , left - sided lt becomes dominant and causes localization of the umbilical portion of pv in the left liver anatomically . therefore , in the case of rslt , the gb was located on its normal site but located to the left of lt and , consequently , was diagnosed according to the conventional definition as being left sided . a recent meticulous anatomic study on this anomaly has already proven both normoposition of the gallbladder and anomalous connection of the ligamentum teres to the right paramedian portal pedicle . therefore , we offer to name this anomaly as a rslt , not as a lsgb . angiographic examination of rslt patients usually shows portal venous anomaly , mostly one of the trifurcation types in which pv , after the first branch running posteriorly , forms a trunk giving off the left and anterior right pvs . this type of anomaly is important especially during a plan of left hepatectomy in which ligation of the portal trunk resulting in lack of portal flow in three - fourth of the liver . although preoperative understanding of rslt and associated anomalies are usually possible with detailed imaging in the case of major surgeries , it is very difficult to show their presence by routine ultrasonography used for cholelithiasis as in our case . laparoscopic cholecystectomy with standard port sites with a lt lift can be performed as in our case , but more medial positioning of the gb retracting port , and placement of the right - hand operating port to the left of the midline is suggested for laparoscopic removal of the gb in the case of rslt . full dissection of calot 's triangle can enable safe completion of the operation laparoscopically . in selective cases , intraoperative cholangiography , antegrade dissection of gb or conversion to the open operation aid in the safe management of an unpredictable confluence of gb into the common bile duct . in conclusion , it is shown that the presence of lt at the right side causes gb to locate to the left but on its normal site . therefore , it is offered to name this anomaly as rslt . as a rare anomaly of the biliary system , it should be investigated in detail because of its association with abnormal intrahepatic portal venous branching . during surgical procedures such as laparoscopic cholecystectomy and hepatectomy , particularly with living donor transplantation , knowledge of rslt helps to surgeon to avoid iatrogenic injuries especially to the portal venous system . in conclusion , it is shown that the presence of lt at the right side causes gb to locate to the left but on its normal site . therefore , it is offered to name this anomaly as rslt . as a rare anomaly of the biliary system , it should be investigated in detail because of its association with abnormal intrahepatic portal venous branching . during surgical procedures such as laparoscopic cholecystectomy and hepatectomy , particularly with living donor transplantation , knowledge of rslt helps to surgeon to avoid iatrogenic injuries especially to the portal venous system .
atypical localization of the gallbladder associated with right - sided ligamentum teres is a rare anomaly of the biliary system . 
 although the conventional nomenclature as being a left - sided gallbladder is usually used , this definition may be incomprehensive because of lacking the anatomical detail . 
 this report describes atypical localization of the gallbladder associated with right - sided ligamentum teres and abnormal intrahepatic portal venous branching , surgically removed laparoscopically .