2. Congenital abnormalities Flashcards
Types of congenital abnormalities
- Anomalies of the Intrahepatic Biliary Tree
- Von Meyenburg Complexes
- Polycystic Liver Disease
- Congenital Hepatic Fibrosis
- Caroli Disease
- Alagille Syndrome - Neonatal Cholestasis
- Neonatal Hepatitis
- Biliary Atresia
Definition of Anomalies of the Intrahepatic Biliary Tree
A heterogeneous group of lesions in which the primary abnormality in altered architecture or paucity of the intrahepatic biliary tree
Von Meyenburg Complexes
- Small clusters of modestly dilated bile ducts embedded in a fibrous stroma located close to or within portal tracts (these lesions are often referred to as “bile duct hamartomas”)
- Relatively common
- No real clinical significance except to be distinguished from metastases to the liver
Polycystic liver disease
- Multiple diffuse cystic lesions in the liver
- Various sizes
- Numbers range from a scattered few to hundreds
- Non-communicating in nature (do not communicate with biliary tract, less risk of malignant transformation) - Associations:
- Cystic lesions in kidney & pancreas
- Strongly associated with AD form of polycystic kidney disease - Clinical features
- Typically asymptomatic
Congenital hepatic fibrosis
- Portal tracts enlarged by irregular, broad bands of collagenous tissue, forming septa that divide the liver into irregular islands
- Variable number of abnormally shaped ducts embedded in fibrous tissue which are in continuity with biliary tree
- Associations:
- Strongly associated with AR form of polycystic kidney disease - Complications:
- Increased risk of cholangiocarcinoma
Caroli disease
- Large ducts of the intrahepatic biliary tree are segmentally dilated & may contain inspissated bile
- Often associated with portal tract fibrosis similar to that seen in congenital hepatic fibrosis - Complications:
- Intrahepatic cholelithiasis
- Cholangitis
- Hepatic abscesses
- Portal hypertension
- Increased risk of cholangiocarcinoma
Alagille Syndrome
- Rare AD multiorgan disorder, with liver involvement manifesting as absence of bile ducts in portal tracts
- 5 main clinical features:
- Chronic cholestasis
- Peripheral stenosis of the pulmonary artery
- Butterfly-like vertebral arch defects
- Posterior embryotoxon (an eye defect)
- Facial dysmorphism (triangular face, deep set eyes, broad nasal bridge)
Definition of neonatal cholestasis
Prolonged conjugated hyperbilirubinemia in the 1st month of life as a result of neonatal hepatitis or biliary atresia
Neonatal hepatitis
Collective term encompassing a variety of disorders causing conjugated hyperbilirubinemia in the neonate:
- Infections (bacterial sepsis, syphilis, toxoplasmosis, HBV, CMV, rubella, HSV)
- Metabolic disorders (alpha1-antitrypsin deficiency, Wilson disease, galactosemia)
- Drug-induced
- Idiopathic
Morphology of neonatal hepatitis
- Cholestasis, mononuclear infiltration, necrosis
- Multinucleated hepatocytic giant cells (formed during hepatocyte regeneration)
- Bile ductal proliferation
Definition of Biliary atresia
Complete obstruction of the lumen of the extrahepatic biliary tree within the first 3 months of life
Pathogenesis of biliary atresia
2 main modes of pathogenesis:
- Fetal form: due to aberrant intrauterine development of the extrahepatic biliary tree
- Perinatal form: due to destruction of normally developed biliary tree following birth (e.g. due to viral infections)
3 main clinical types of biliary atresia
- Type I: limited to common bile duct
- Type II: limited to the hepatic bile ducts
- Type III: includes obstruction of bile ducts at/above
the level of the porta hepatis
Morphology of biliary atresia
- Severe cholestasis
- Marked bile ductular proliferation
- Inflammatory cellular infiltration (neutrophilic)
- Biliary fibrosis
- Biliary cirrhosis
Treatment of biliary atresia
- Hepatic porto-enterostomy (Kasai procedure – involves bypassing of segment of atresia by creating an anastomosis): for types I & II
- Liver transplantation: for type III
