Abstract
BACKGROUND: To date, no studies have sought to determine the frequency of malignancy in patients presenting with a putative biliary stricture and normal liver function tests (LFTs). The primary aim of this retrospective cohort study was to determine the likelihood of malignancy in patients presenting with a biliary stricture and normal LFTs, a normal bilirubin level either alone or in combination with normal levels of liver enzymes [alkaline phosphatase (ALP) and alanine transaminase (ALT)]. A secondary aim was to determine any clinical/biochemical/sonographic features that may be associated with malignancy. METHODS: Patients presenting over a 10-year period were included. Fifteen variables were analysed to determine their association with malignant disease. RESULTS: Eight hundred and thirty patients with putative biliary strictures were included. Primary hepatopancreaticobiliary (HPB) cancers presented with a normal bilirubin and normal liver enzymes (ALP and ALT) in 6% of cases. Patients with a putative biliary stricture and a normal bilirubin level whose final diagnoses were pancreatic cancer, ampullary cancer, distal cholangiocarcinoma and hilar cholangiocarcinoma represented 21%, 13%, 7% and 9% of individuals diagnosed with these pathologies, respectively. Hypoalbuminaemia and isolated intrahepatic duct dilatation on ultrasound were significantly associated with malignancy in patients with normal bilirubin and completely normal LFTs. CONCLUSIONS: This study has shown that patients with a putative biliary stricture and completely normal LFTs are unlikely to have a primary HPB malignancy. Those presenting with a normal bilirubin level, but deranged liver enzymes (ALP and/or ALT), are more likely to have malignant disease, and this should necessitate a higher degree of clinical suspicion.