The neuroendocrine tumors of the pancreatic pancreas, pNET, represent a significant challenge for the radiologist, who is equally committed to evaluating local extension and remote localization in malignant, generalized forms that are not syndromic and therefore frequently at an advanced stage of diagnosis, or to researching very small lesions in patients with the typical clinical syndrome.

In particular, these tumors are often associated with congenital/hereditary syndromes (e. g. MEN 1, VHL, etc.) with a more frequent multifocal presentation.
The distinction between neuroendocrine cancer and other forms of solid pancreatic cancer, such as adenocarcinoma, is crucial from a diagnostic point of view for different prognosis and is based on its histological peculiarities.

The presence of numerous blood vessels in the context of stroma collagen determines the typical hypervascular aspect of imaging, most frequent in small tumors.

However, other factors play a role in defining the characteristics of these tumors, first of all the following dimensions: the tumors of more significant size are those that often undergo bleeding and necrosis, with consequent structural inhomogeneity and calcium deposits, and in which signs of local extension are associated with vascular infiltration, lymphadenopathy and metastasis at a distance.

The case presented has a double challenge considering the small rounded-shape mass inside the tail of the pancreas suspected to be a cystadenoma (not yet confirmed)