[A peculiar anomaly of the main biliary duct: choledochal cystic dilatation]

The Authors report a case of choledochal cystic dilatation and examine this particular anomaly of the main biliary duct analysing the complex classification. After a brief review of the embryology of the hepato-pancreatic ring, etiopathogenetic theories, clinic characteristics, as well as diagnostic and therapeutic possibilities for this affection are taken into account. It is concluded that the best therapeutic choice should be always based on an accurate evaluation of the anatomo-pathological conditions in each single case.