Still elusive: Developments in the accurate diagnosis of indeterminate biliary strictures

Table 1 Aetiology of biliary strictures

Benign		Malignant
1 Stone disease	Choledocholithiasis, Mirizzi syndrome	1 Pancreatic cancer; 2 Cholangiocarcinoma; 3 Gallbladder cancer; 4 Duodenal cancer; 5 Hepatocellular cancer; 6 Lymphoma; 7 Metastatic disease
2 Inflammation	Chronic pancreatitis, Histiocytosis, Mast cell cholangiopathy
3 Autoimmune	IgG4 cholangiopathy, Primary sclerosing cholangitis, Sarcoidosis
4 Iatrogenic	Liver transplantation, Post-cholecystectomy, Whipple’s procedure, Radiation injury, Medication (e.g. Ketamine)
5 Infection	AIDS cholangiopathy, Recurrent cholangitis, Trematodiasis/flukes (e.g. Clonorchis sinensis, Fasciola)
6 Vascular	Vasculitis, Ischaemic cholangiopathy, Sickle cell disease hepatopathy, Choledochal varices