Due to the genetic background of the disease, every single neuroendocrine cell of the pancreas is a potential progenitor of neuroendocrine tumors (NETs). More than 90% of patients with multiple endocrine neoplasia type 1 (MEN1) develop multiple pancreatic neuroendocrine tumors (pNETs) "viewable" by transgastric endosonography and/or cross sectional and/or functional imaging. These tumors are the most common cause for premature death in MEN1 (1, 2).