A rare cause of persistent cholestatic jaundice: gallbladder amyloidosis.

Gallbladder amyloidosis is an exceptionally rare condition that may clinically mimic extrahepatic cholestasis. An 81-year-old man presented with persistent cholestatic jaundice and recurrent right upper quadrant pain. Laboratory evaluation showed conjugated hyperbilirubinemia and elevated cholestatic liver enzymes without signs of inflammation. Imaging studies, including ultrasound, MRCP, and CT, demonstrated gallstones and gallbladder wall thickening but no bile duct dilation or obstruction. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound were unremarkable. Because of ongoing pain and cholestasis, laparoscopic cholecystectomy was performed. Histopathological examination revealed chronic fibrosing cholecystitis with marked submucosal and vascular deposition of amorphous eosinophilic material, showing apple-green birefringence under polarized light after Congo red staining, consistent with amyloid. Immunohistochemistry favored transthyretin (ATTR) amyloid deposition. Postoperatively, the patient recovered uneventfully with resolution of pruritus and normalization of bilirubin. Extensive systemic evaluation excluded generalized amyloidosis, indicating a localized form of gallbladder amyloidosis. This case underscores the importance of considering infiltrative diseases such as amyloidosis in the differential diagnosis of unexplained cholestatic jaundice, particularly when imaging fails to show mechanical obstruction. Recognition of this entity may prevent unnecessary invasive interventions and emphasizes the diagnostic value of histopathological confirmation following cholecystectomy.