Localized cystic dilatation of the intrahepatic bile ducts as a distinct subtype of Caroli disease: a case report.

BACKGROUND

Caroli disease encompasses multiple distinct entities. We report two cases of localized cystic dilatation of the intrahepatic bile ducts exhibiting a unique morphology.

CASE PRESENTATIONS: Both patients were Japanese, diagnosed with a cyst in the liver prenatally (27 weeks' gestation) and at 3 months of age. The dilatation was limited to the anterior section branch and its first upstream branches, and the cystically dilated bile ducts abruptly connected to normal-sized ducts on both the upstream and downstream sides. One case transiently had debris in the dilated duct during the neonatal period, but did not present any symptoms. The patients have remained asymptomatic for 10 years (case 1) and 9 years (case 2).

CONCLUSION

This case report presents a distinct entity separate from other forms of Caroli disease, namely, localized cystic dilatation of the intrahepatic bile ducts. In total, 12 cases, along with 10 similar cases from literature, were assessed.