P1128 - AA Amyloidosis of the Gallbladder and Biliary Tree Mimicking Cholangiocarcinoma

Rohit Khanna, DO¹, Alex Prevallet, DO¹, Julio Guitierrez, MD^2
1Scripps Mercy Hospital, San Diego, CA; ²Scripps Clinic, La Jolla, CA

Introduction: AA amyloidosis, a rare protein depositing condition, can affect the gastrointestinal tract with primary liver amyloidosis being well described in the literature. We present a rare case of biliary amyloidosis, with a total of 15 documented cases found in the literature. The patient presented below would be the 16th recorded case.

Case Description/Methods: This is a 71-year-old male with history of rheumatoid arthritis that presented with one week of generalized weakness, arthralgias, diarrhea, jaundice, and oliguria. Notable labs include an elevated alkaline phosphatase (ALP), total bilirubin, ferritin, ALT, and creatinine. CEA and CA-19-9 were markedly elevated. Concerned for cholangiocarcinoma, MRCP revealed common bile duct debris, sludge and liver hypoattenuation, indicative of possible hemochromatosis. EUS and ERCP revealed pericholecystic thickening, biliary sludge, and ductal dilation of common hepatic and main duct with a 5-mm supra-ampullary stricture. Subsequent laparoscopic cholecystectomy was performed for continued concern for cholangiocarcinoma along with cholecystitis and hemochromatosis. Intraoperative biopsy demonstrated amyloid present on Congo red stain in submucosal and mural vessels within the gallbladder and within the hepatic vessels with no malignant lesions. AA amyloidosis was confirmed with immunohistochemistry.

Discussion: To our knowledge, this is the first case of amyloidosis of the gallbladder and biliary tree mimicking cholangiocarcinoma as seen by the elevations of ALP, liver enzymes, total bilirubin, CEA, and CA 19-9. It is presumed, given the extensive spread of the patient’s disease, that amyloid fibrils would be found throughout the biliary tree as the ERCP demonstrated a supra-ampullary stricture biliary duct brushings showing extensive inflammation. Additionally, submucosal and mural vessel amyloid deposition, without apparent biliary wall amyloid deposition, was seen on gallbladder biopsy. This likely represents amyloid deposition within the biliary vessels leading to necrotizing cholecystitis causing biliary stasis. A literature review of five biliary AA amyloid patients demonstrates similar findings, with amyloid deposition within the submucosa of the vessel walls. While clinical recognition of amyloidosis has become more common in recent years, more research is warranted to uncover the pathophysiologic role amyloid deposition has in the gallbladder and biliary tree.


Figure: Top photo: Histopathology of cholecystectomy specimen showing amyloid deposition around the gallbladder submucosal and mural vessels, along with pericholecystic adipose tissue. Bottom photo: Congo-phillic tissue confirming amyloid deposition within the submucosal and mural vessels of the cholecystectomy specimen


Disclosures:
Rohit Khanna indicated no relevant financial relationships.
Alex Prevallet indicated no relevant financial relationships.
Julio Guitierrez indicated no relevant financial relationships.


Rohit Khanna, DO¹, Alex Prevallet, DO¹, Julio Guitierrez, MD². P1128 - AA Amyloidosis of the Gallbladder and Biliary Tree Mimicking Cholangiocarcinoma, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.