P0106 - Primary Amyloidosis Presenting as Non-Obstructive Biliary Dilation

Alisha Sharma, MD¹, Aslam Syed, MD², Tavankit Singh, MD^1
1Allegheny General Hospital, Pittsburgh, PA; ²Allegheny Health Network, Pittsburgh, PA

Introduction: Amyloidosis is characterized by extracellular deposition of insoluble proteins. Primary amyloidosis is a subtype with liver involvement seen in 70% of the cases. Cholestasis is a rare occurrence described by presence of focal amyloid deposition in the bile ducts leading to biliary obstruction. We present an unusual case of amyloidosis presenting with intra and extrahepatic biliary ductal dilation with no evidence of biliary obstruction.

Case Description/Methods: A 64 year-old female presented with 3 months of abdominal distension and lower extremity edema. She had a past medical history of cholecystectomy at age 47 and a Roux-en-Y gastric bypass at age 50. Physical examination revealed abdominal distension and gross peripheral edema. Lab work demonstrated ALP 529 U/L, AST 19 U/L, ALT 15 U/L, albumin 1.4 g/dl, total bilirubin 0.2 mg/dl, serum creatinine 1.8 mg/dl. Autoimmune panel returned negative. Liver ultrasound revealed homogenous liver with intra and extrahepatic biliary tree dilation, CBD measuring 15 mm, and moderate amount of ascites. Paracentesis demonstrated SAAG < 1.1 g/dl. This, along with elevated creatinine, raised suspicion for nephrotic syndrome.

A renal biopsy was performed that revealed extensive mesangial expansion with amorphous material that stained positive with Congo red suggestive of amyloidosis. Further analysis confirmed AL amyloid (kappa subtype). Further bone marrow biopsy revealed hypercellular marrow, excess of plasma cells and a positive congo red stain confirming amyloidosis. Patient’s ALP increased to 1478 U/L. MRCP revealed moderate to severe intra and extrahepatic biliary dilation with CBD measuring 14-mm without evidence of obstruction. ERCP was not performed and considered challenging given patient’s Roux-en-Y-anatomy. Patient was initiated on chemotherapy with cyclophosphamide, bortezomib and dexamethasone (CyborD) and daratumaab in anticipation of eventual stem cell transplant.

Discussion: Intrahepatic biliary dilation has been previously reported as a result of impedance to bile flow due to amyloid deposition. Rare cases of extrahepatic cholestasis have also been reported wherein amyloid presenting as ‘amyloidoma’ results in mass effect causing CBD obstruction. In our case, there was presence of both intra and extrahepatic biliary dilation without laboratory or radiographic evidence of obstruction. Given amyloidosis has a high mortality if left untreated, it is important to consider it in the differential diagnosis for unexplained biliary duct dilation.



Disclosures:


Alisha Sharma, MD¹, Aslam Syed, MD², Tavankit Singh, MD¹. P0106 - Primary Amyloidosis Presenting as Non-Obstructive Biliary Dilation, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.