This approach is reasonable for sporadic PNENs that almost always occur as a single tumor, while MEN1 patients are affected, in the great majority of cases, by multiple, often small, concurrent F-PNENs and/or NF-PNENs, scattered through the endocrine pancreas and the duodenal wall, which may be missed during conventional imaging and are recognized only during the surgical intervention [23]. This evidence concerns the gene MEN1 and neoplasm.