Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (197 page)

   Hypercholesterolemia (e.g., DM, malabsorption)

   Chronic hemolytic disease (e.g., hereditary spherocytosis)

   Laboratory findings due to complications (e.g., cholecystitis, choledocholithiasis, gallstone ileus)

ATRESIA, EXTRAHEPATIC BILIARY, CONGENITAL

   Conjugated serum bilirubin increased in early days of life in some infants but not until 2nd week in others. Level is often <12 mg/dL during the first few months, with subsequent rise later in life.

   Laboratory findings as in complete biliary obstruction.

   Liver biopsy to differentiate from neonatal hepatitis.

   Laboratory findings due to sequelae (e.g., biliary cirrhosis, portal hypertension, frequent infections, rickets, hepatic failure).

   
¹³¹
I-rose bengal excretion test.

OTHER CONSIDERATIONS

   Most important to differentiate this condition from neonatal hepatitis, for which surgery may be harmful.

   More than 90% of cases of extrahepatic biliary obstruction in newborns are due to biliary atresia; occasional cases may be due to choledochal cyst (causes intermittent jaundice in infancy), bile plug syndrome, or bile ascites (associated with spontaneous perforation of the common bile duct).

INTRAHEPATIC OBSTRUCTION CHOLESTASIS

   Causes of intrahepatic cholestasis:

   Intrahepatic obstruction

   Space-occupying lesions (e.g., amyloidosis, sarcoidosis, metastases; non-Hodgkin lymphoma more often than Hodgkin disease)