Segmental Caroli’s Disease in Autosomal Dominant Polycystic Kidney Disease: A Rare Association

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a common disorder characterised by progressive renal cyst formation and other extrarenal manifestations, while Caroli’s disease is a rare autosomal recessive disorder involving intrahepatic bile duct dilatation with its segmental variant being exceptionally uncommon. We report a 40-year-old man with known ADPKD who, during MRI-based renal volumetry, was incidentally found to have segmental Caroli’s disease involving hepatic segments V and VI, demonstrated by localised biliary dilatations and the characteristic “central dot sign.” Laboratory tests revealed mildly impaired renal function but normal liver parameters. This case highlights a rare phenotypic overlap between distinct ciliopathy disorders, underscoring the need for further research into shared genetic or modifying factors influencing bile duct morphogenesis in ADPKD.