Cholangiocarcinoma in a 17-year-old boy with primary sclerosing cholangitis and UroVysion™ fluorescent in situ hybridization.

Primary sclerosing cholangitis (PSC) is uncommon in the younger age range and bile duct brushing cytology can present unique challenges. We describe the case of a 17-year-old boy with a new diagnosis of PSC who presented with cholangiocarcinoma. The clinical history, endoscopic features, cytomorphologic findings, and results of UroVysion™ fluorescent in situ hybridization (FISH) on the bile duct brush are described. UroVysion FISH on bile duct brushings is an ancillary study that can improve the diagnostic sensitivity for malignancy, specially in challenging cases where the cytomorphologic or clinical characteristics of the case are not typical. The occurrence of cholangiocarcinoma in young age group with PSC is uncommon, and the utilization of UroVysion FISH has been rarely described.