The Gastrointestinal System, Including the Biliary Tract, Pancreas, and Liver

Abstract

Cytology of the gastrointestinal (GI) and hepatobiliary systems has been revolutionized over the last few decades with the development of fiberoptic endoscopic ultrasound as well as advances in sampling devices. When compared to biopsy, cytological brushing of a lesion in direct view offers the advantages of greater coverage of a diseased area, enabling greater sensitivity in the diagnosis of infections such as candida and H. pylori as well as the need for a single diagnostic sample rather than multiple biopsies from different sites, immediate assessment of adequacy, and the potential for rapid on-site diagnosis. Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) techniques allow access to deep-seated lesions, such as those causing extrinsic compression, and to organs or structures that are difficult to sample percutaneously. Cytological diagnosis offers high accuracy and safe sampling in lesions of the esophagus, stomach, and pancreas. Anal cytology has potential for development as a screening tool in populations at risk for anal carcinoma.