Pancreatic neuroendocrine tumors: A case-based evidence review.

Pancreatic neuroendocrine tumors (pNETs) are rare, presenting significant challenges in timely diagnosis and subsequent treatment. The clinical and pathobiological behavior of these tumors varies significantly, making follow-up and therapeutic approaches challenging for clinicians. Although the majority of these neoplasms are hormonally inactive, some can be associated with endocrine dysfunction. Very rarely, a nonfunctional tumor can later become hormonally active, further complicating prognostication and management. Depending on the character of the disease, clinical picture and prognosis, different treatment modalities are instituted with varying effectivities. We recently came across a unique case of nonfunctioning malignant pNET at an advanced stage, metastatic disease upon diagnosis, managed medically with somatostatin analog therapy (Octreotide) and targeted therapy (Everolimus) with stable disease for 40 months that subsequently turned out to become functional (insulinoma). With the aid of this unique case, we update the current clinical, diagnostic and therapeutic approach to pNETs in this evidence-based review.