RESUMEN
Pancreas of Beagle dogs deriving from 166 male and 166 female animals were examined microscopically and were found to show nesidioblastosis-like structural alteration in 29 dogs. The lesion was represented by endocrine and ductular epithelial cell proliferation. The incidence profile and the severity of the changes observed were closely associated with the age of the dogs, younger dogs being more often and more seriously affected than older dogs. No link with altered insulin function has been established as serum glucose levels were found to be within the normal range. The pathology of spontaneous extra-islet endocrine cell proliferation in the young Beagle dogs, described in this study, has some similarities to that of nesidioblastosis of human neonates and infants.