Abnormalities in number, size, and shape of the gallbladder occasionally occur. Infants and children may demonstrate hypoplasia of the gallbladder, which appears as little more than a small, rudimentary pouch at the end of the cystic duct. Congenital multiseptate gallbladder is a hyperplastic structure with multiple inter-communicating septa dividing the lumen of the gallbladder. It appears on oral cholecystography as a small gallbladder with a honeycomb pattern. Stasis of bile in a multiseptate gallbladder predisposes to infection and gallstone formation. The Phrygian cap is a develop¬mental anomaly in which an incomplete septum extends across the fundus of the gallbladder, partially separating it from the body. Although of no clinical significance, this congenital deformity must be differentiated from localized adenomyomatosis. Anomalies of position in-clude left-sided gallbladder, intrahepatic gallbladder, and the “floating” gallbladder, which may predispose to acute torsion, volvulus, or herniation of the gallbladder.
A choledochal cyst is a cystic or fusiform dilatation of the common bile duct and adjacent portions of the com¬mon hepatic and cystic ducts that is typically associated with localized constriction of the distal common, bile duct. Concomitant dilatation of intrahepatic bile ducts has recently been recognized with increasing frequency. Although usually considered to be a congenital, devel¬opmental abnormality, many choledochal cysts are probably acquired lesions caused by regurgitation of pancreatic secretions into the distal common bile duct, leading to cholangitis, gradual stricture formation, and ductal dilatation over a long period. Clinically, chole¬dochal cysts are classically described as presenting with a triad of abdominal pain, right upper quadrant mass, and jaundice.
A soft tissue mass representing the markedly dilated bile duct is often seen on plain abdominal radiographs. An upper gastrointestinal examination can demonstrate generalized widening of the duodenal sweep or displacement of the duodenum anteriorly, inferiorly, and to the left. Contrast material administered via percutaneous transhepatic cholangiography can fill the dilated biliary system.
Ultrasound, computed tomography (CT), and radionuclide scanning with iminodiacetic acid derivatives are all noninvasive techniques that can establish the diag-nosis of choledochal cyst.
Biliary atresia is the most common cause of persistent neonatal jaundice. Children with this anomaly generally have an unfavorable prognosis. The entire extrahepatic biliary ductal system is usually atretic, though the common hepatic duct or common bile duct may be individually involved. Ultrasound may be of value in demonstrating dilatation of the bile ducts and in excluding a choledochal cyst. The diagnosis is confirmed by surgical exploration with operative cholangiography, which demonstrates dilatation of the biliary tree proximal to the point of atresia.gallbladder phrygian cap deformity · intrahepatic localization gallbladder ·