Defining the diagnostic algorithm in pancreatic cancer.

Most patients with pancreatic cancer present with a mass on radiologic studies, however, not every pancreatic mass is cancer. Since radiological studies alone are insufficient to establish the diagnosis of a pancreatic mass and patient management depends on a definitive diagnosis; confirmatory cytology or histology is usually required. As a minimally invasive procedure, EUS and EUS FNA avoid the risk of cutaneous or peritoneal contamination that may occur with CT or US-guided investigations and is less invasive than surgical interventions. As a result, EUS FNA of pancreatic masses is becoming the standard for obtaining cytological diagnosis. This chapter presents an EUS-based diagnostic algorithm for the evaluation of pancreatic lesions and is based upon a review of the pertinent literature in the field of pancreatic endosonography that has been the most influential in helping to guide this evolving field. Realizing there is much overlap among the EUS characteristics of various pancreatic lesions, for the sake of simplicity we have structured our discussion in broad terms of solid versus cystic lesions and discuss various pancreatic lesions within this framework. The additional contributors to this round table discussion have been asked to provide a more dedicated, focused discussion of the various subcategories of pancreatic lesions in greater detail than we could hope to achieve here. We provide this final contribution to the round table as a means of bringing the discussion back to the big picture of pancreatic lesions, rather than trying to hone in on the fine details of any one subclass.