Focal Intrahepatic Duct Dilatation (FIDD): a Finding That Mandates Further Evaluation That May Amount to Liver Resection

The increasing use of imaging has led to incidental findings in the liver. The Western experience of managing focal intrahepatic duct dilatation (FIDD) is not well recorded. We present our experience based on a large prospectively maintained database at a tertiary hepatobiliary surgical unit. We identified patients with liver resection for focal incidental duct dilatation from January 2003 to December 2019 from the liver unit database. We recorded the demographics, symptomatology, blood test results, imaging, type of liver resection, morbidity, mortality and histology of resected specimens. Nine patients had focal intrahepatic duct dilatation among 994 liver resections performed (0.9%). Six patients were asymptomatic, 2 upper abdominal pain and 1 recurrent gram-negative sepsis. Liver function tests were normal in all patients. Two patients had cholangiocarcinoma (CCA), 4 intrahepatic stones, 1 intraductal papillary neoplasm of bile duct (IPN-B) and 2 benign strictures. Focal incidental duct dilatation is rare in the Western population. Most patients are asymptomatic with an incidental finding of intrahepatic duct dilatation on cross-sectional imaging. Differentiating benign and malignant pathology is difficult warranting liver resection, in fit patients, to resolve the diagnosis. Liver resection is safe and can be potentially curative in patients with a neoplasm, which can occur in 30% of patients with focal intrahepatic duct dilatation.