LAUSR

Objectives Pancreatic neuroendocrine neoplasias (pNENs) in multiple endocrine neoplasia type 1 are predominantly found in the dorsal anlage. Whether their growth velocity and incidence might be related to their location in the pancreas has not been investigated yet. Methods We studied 117 patients using endoscopic ultrasound. Results Growth velocity could be calculated for 389 pNENs. Increase of largest tumor diameter (% per month) was 0.67 (standard deviation [SD], 2.04) in the pancreatic tail (n = 138), 1.12 (SD, 3.00) in the pancreatic body (n = 100), 0.58 (SD, 1.19) in the pancreatic head/uncinate process—dorsal anlage (n = 130), and 0.68 (SD, 0.77) in the pancreatic head/uncinate process—ventral anlage (n = 12). Comparing growth velocity of all pNENs in the dorsal (n = 368, 0.76 [SD, 2.13]) versus ventral anlage, no significant difference was detected. Annual tumor incidence rate was 0.21 in the pancreatic tail, 0.13 in the pancreatic body, 0.17 in the pancreatic head/uncinate process—dorsal anlage, 0.51 dorsal anlage together, and 0.02 in the pancreatic head/uncinate process—ventral anlage. Conclusions Multiple endocrine neoplasia type 1 pNENs are unequally distributed between ventral (low prevalence and incidence) and dorsal anlage. However, there are no regional differences in growth behavior.