Chronic pancreatitis: Focal pancreatitis or cancer? Is there a role for FNA/biopsy? Autoimmune pancreatitis

The lack of pathognomonic imaging features, considerable variation in pancreatic imaging, and diverse spectrum of clinical disease highlight the need for safe measures for acquiring core tissue specimens to enhance the diagnostic accuracy of AIP. Our initial experience supports the assumption that tissue obtained with EUS TCB is sufficient to allow adequate histologic review to diagnose AIP. The findings are useful in guiding management and may prevent misdiagnosis of pancreatic carcinoma risking lost opportunity for potentially curative resection while avoiding unnecessary surgical interventions for those with AIP. While these findings clearly indicate the ability of EUS TCB to establish the diagnosis of AIP, the limited number of patients evaluated prohibits any determination of sensitivity, specificity or safety in this setting. We favor EUS TCB for patients with a compatible clinical presentation in whom there is diagnostic uncertainty when the finds are likely to alter management. However, future study is needed in this cohort of patients to establish the: 1) performance characteristics of EUS and tissue sampling and intraductal ultrasound, 2) safety of EUS guided tissue sampling and intraductal ultrasound, and the 3) possible role of ultrasound contrast and power Doppler.