Though exact incidence is not mentioned in different small study, yet gallbladder agenesis without other parts of
biliary apparatus occurs in 0.02-0.04% in average [2] and this commonly appear in association to other congenital or developmental abnormalities like congenital heart diseases and lung diseases.
This hepatic diverticulum extends into the septum transversum, where it enlarges and divides into two parts: the larger cranial portion (Pans hepatica), which further divides to form the liver cells and intrahepatic
biliary apparatus of the right and left hepatic lobes, and the smaller caudal portion (Pars cystica), which gives rise to the gallbladder and the cystic duct.