Autoimmune Pancreatitis

The initial description of autoimmune pancreatitis (AIP) highlighted the presence of obstructive jaundice secondary to a pancreatic head mass mimicking pancreatic cancer. The classic EUS finding in AIP is diffuse pancreatic enlargement with a hypoechoic, coarse, patchy, heterogeneous appearance. This chapter reviews the spectrum of AIP features identified by EUS and suggests a potential role of endoscopic ultrasound (EUS)-guided tissue sampling. The classic EUS finding in AIP is diffuse pancreatic enlargement with a hypoechoic, coarse, patchy, heterogeneous appearance. Although the use is not widespread, some image-enhancing techniques employed during EUS may be used to help differentiate AIP from pancreatic cancer. Cytologic specimens obtained during EUS-guided fine needle aspiration (EUS-FNA) of the pancreas are often inadequate for diagnosing AIP. Some suggest that the main role of EUS-FNA is to exclude pancreatic adenocarcinoma rather than to diagnose AIP.