Diagnosis of malignant biliary strictures

It is important to determine the benign or malignant nature of a biliary stricture, and a tissue diagnosis is usually desirable. This article discusses methods for diagnosis of malignant biliary strictures, including bile cytology, biliary brush cytology, intraductal forceps biopsy, needle aspiration, scraping devices, and endoscopic ultrasound-guided aspiration. Ki-ras analysis and the use of flow cytometry are also reviewed. In most cases a combination of tissue sampling techniques will result in the highest diagnostic yield.