Endoscopy and Endoscopic Ultrasound in Assessing and Managing Neuroendocrine Neoplasms

Despite advances in radiological and metabolic imaging, standard axial endoscopy and endoscopic ultrasonography (EUS) still play a pivotal role in a number of neuroendocrine neoplasms (NENs) of the gastrointestinal and duodenopancreatic region. Upper gastrointestinal endoscopy is essential for the detection and characterization of NEN up to the angle of Treitz (esophageal, gastric and duodenal). Ileocolonoscopy allows the assessing and diagnosing of rectal, colonic and very occasionally distal ileal lesions. Endoscopic assessment is the mainstay for diagnosing gastric NENs associated with hypergastrinemia, but is also useful in detecting and diagnosing duodenal NENs (both functional and nonfunctional) and ampullary NENs. As rectal NENs are on the increase, standard colonoscopy (often combined with endorectal EUS) is also useful in detecting and treating small rectal NENs. EUS is the modality of choice for diagnosing pancreatic NENs and for locoregional staging of esophageal, gastric, duodenal, pancreatic and rectal NENs. This chapter will expand on the diagnostic and therapeutic role of endoscopy and EUS in the field of gastrointestinal and pancreatic NENs.