A rare case of resection of a mucinous cystic neoplasm originating from the extrahepatic bile duct with cholangioscopic imaging

TL;DR

A rare case of a bile duct tumor was diagnosed using cholangioscopy, offering new insights into diagnosing and treating biliary neoplasms.

Contribution

This is the first report of cholangioscopic imaging used to identify a biliary mucinous cystic neoplasm.

Findings

Cholangioscopy revealed translucent oval masses with capillary vessels in the bile duct.

Histological and immunohistochemical analysis confirmed a mucinous cystic neoplasm with low-grade intraepithelial neoplasia.

The case highlights the utility of cholangioscopy in diagnosing and guiding treatment for biliary tumors.

Abstract

A 29‐year‐old woman was admitted to our hospital for examination of obstructive jaundice and an extrahepatic bile duct lesion. Contrast‐enhanced computed tomography revealed a 20 mm cystic lesion with a thin external capsule in the common hepatic duct. Cholangioscopy revealed translucent oval masses with capillary vessels attached to the bile duct walls. The surface was mostly smooth yet partially irregular with redness, suggesting that the masses were epithelial neoplasms. Histological findings of cholangioscopy‐guided targeted biopsies of the mass showed subepithelial spindle cell proliferation with no atypical epithelium. The patient underwent an extrahepatic bile duct resection to confirm the pathological diagnosis. Immunohistochemistry of surgical specimens revealed that the spindle cells were positive for estrogen and progesterone receptors. Finally, the cystic lesion with ovarian‐like stroma was diagnosed as a mucinous cystic neoplasm with low‐grade intraepithelial neoplasia. This is the first report of cholangioscopic imaging of a biliary mucinous cyctic neoplasm. Cholangioscopic imaging can be helpful in the differential diagnosis of biliary neoplasms and in the determination of treatment strategies.

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