Nonfunctional neuroendocrine tumor of the pancreas: Case report and review of the literature

Abstract

Introduction: Pancreatic neuroendocrine tumors (PNET) have an incidence of one per 100,000 individuals per year. They represent about 1-2% of all pancreatic tumors. PNETs are a heterogeneous group with various clinical presentations and lineage. Non functional PNET (NF-PNET) are incidentally discovered in most cases. This article presents a review of NF-PNET and the case of a patient with this disease, in addition to its diagnosis, clinical presentation, and treatment.

Presentation of case: The patient is a 37-year-old asymptomatic man who was sent from his reference unit because of a pancreatic tumor that was visualized incidentally during a laparotomy performed three months before due to an acute abdomen secondary to blunt abdominal trauma. A CT scan was requested that showed a retroperitoneal mass 7.5cm×6.6cm×7cm with infiltration of the duodenal wall. Endoscopy was performed, which reported a duodenal ulcer with nonconclusive histological findings. A percutaneous biopsy was obtained out and a diagnosis of a neuroendocrine tumor was made. Chemotherapy was started because infiltration of the portomesenteric axis was suspected. The patient presented signs of toxicity during his third cycle and therefore was scheduled for exploratory laparotomy. Pancreatoduodenectomy was performed with a histologic diagnosis of a pancreatic neuroendocrine tumor.

Discussion: The presentation of a NF-PNET is nonspecific. They continue to be tumors with a low incidence and few studies directed toward early detection and management have been carried out. Currently, CT scans are the studies most used for detection.

Conclusion: Surgical treatment is preferred in patients without evidence of unresectability with longer survival. The characteristics of NF-PNETs make their detection difficult and new strategies are needed for early detection and management. New studies in early stages with new cytotoxics or analogs are promising.

Fig. 1

CT scan showing retroperitoneal lesion at the level of the pancreas with duodenal and large vessel compression.

Fig. 2

Surgical images that show the neuroendocrine lesion that involves the head of the pancreas with infiltration and compression of the second and third portion of the duodenum; (a) arrow indicating the portal vein; (b) arrow showing the lesion.

Fig. 3

Fixed macroscopic specimen of pancreatic neuroendocrine tumor: (a) sagittal view; (b) posterior view where portions of the duodenum, the gall bladder and the biliary canal are seen.

Fig. 4

Positive immunohistochemistry reaction: (a) chromogranin positive; (b) synaptophysin positive. Both are diagnostic of pancreatic neuroendocrine tumors (400×).