Snapshot A 22-year-old motorcycle accident victim with unknown past medical history is brought into the ED with severe head injuries. He is stabilized and brought to the surgical ICU where he is deemed to be brain dead by both the intensivist and neurosurgery staff. The organ transplant team is contacted and determine that he is an eligible kidney donor. However, he is not eligible for liver donation. Upon entering the abdomen during harvest, the team notices that his liver is black. Introduction Hereditary conjugated hyperbilirubinemia ↓ hepatic excretion of conjugated bilirubin autosomal recessive Two types Dubin-Johnson syndrome (DJS) mutation of the canalicular multiple drug-resistance protein (MRP2) gene leads to impaired biliary excretion of bilirubin glucuronides grossly "black liver" Rotor syndrome associated with mutations of the SLCO1B1 and SLCO1B3 genes leading to defect in the hepatic storage of conjugated bilirubin does not cause black liver Presentation Symptoms most patients are asymptomatic Physical exam may become jaundiced or icteric during pregnancy or with oral contraceptives jaundice is non-pruritic Imaging Dubin-Johnson syndrome gallbadder and biliary system cannot be visualized via oral cholecystography Rotor syndrome galllbadder can be visualized via oral cholecystogram Studies Laboratory studies normal laboratory studies including hepatic function, alkaline phosphatase, and albumin elevated conjugated bilirubin levels with total serum bilirubin concentrations between 2-5 mg/dL coproporphyrin III:coproporphyrin I ratio elevated coproporphyrin I ration in DJS total urine coproporphyrin levels elevated in Rotor syndrome normal in DJS Gross pathology dark black liver in DJS due to deposition of dense pigment Treatment Benign condition No treatment required