Narrowing the differential — abnormal labs in a transplant recipient

60-year-old male with history of HCV cirrhosis s/p deceased donor liver transplant with duct-to-duct biliary anastomosis six months ago presents with jaundice, dark urine, pruritus, and pale stools. Exam is notable for icterus. Labs revealed a total bilirubin of 10 mg/dL, direct bilirubin 5 mg/dL, ALP 538 u/L, AST 36 u/L, and ALT 41 u/L. INR is 1.0. Labs from three weeks prior were notable for a normal bilirubin and mildly elevated ALP to 181 u/L which has been rising. Doppler ultrasound reveals coarsened hepatic echotexture, patent vessels, and intrahepatic biliary dilatation to 1cm.

What is the next best step?

Biliary Ductal Dilation: Just Another Case of Malignancy?

A 47-year-old male presents with painless jaundice.  He also reports decreased appetite and energy, along with diffuse itching, pale stools, and dark urine. He denies any weight loss or history of liver disease. His physical exam is notable for jaundice and his labs show cholestasis (total bilirubin 6.3, primarily conjugated, and alkaline phosphatase of 347) and elevated transaminases (AST 160 and ALT 547). A MRCP shows intra-hepatic biliary dilation and retroperitoneal fibrosis without a mass or filling defect

What is the most likely underlying diagnosis?