2025 Volume 39 Issue 4 Pages 668-675
A 70-year-old man with a history of cholecystectomy who has abdominal discomfort had undergone abdominal ultrasound at another medical clinic, revealing dilatation of the intrahepatic bile ducts and a tumorous lesion in the upper bile duct. He presented to our department with normal blood test results, but CT/MRCP had identified a tumor at the gallbladder duct bifurcation. Endoscopic ultrasound (EUS) revealed a 13mm hypoechoic tumor with internal echogenic foci and septations at the same site. Although neurofibroma was suspected, biopsy during endoscopic retrograde cholangiopancreatography showed clustering of nerve fibers within the fibromuscular layer, making differentiation between typical nerve fibers and neurofibroma challenging. Surgical resection was performed because of potential biliary stricture. Neurofibroma was diagnosed based on results of histopathological examination, with support of EUS findings revealing internal fibrosis, which are uncommon in typical biliary malignancies. These results demonstrate that EUS findings can aid in neurofibroma diagnosis.
