Indium-111 pentetreotide uptake by pancreatic polypeptide cell hyperplasia: potential pitfall in somatostatin receptor scintigraphy.

A 71-year-old man with duodenal gastrin cell tumor was being evaluated for residual/metastatic disease. Somatostatin receptor scintigraphy (SRS) identified a 2-cm area of focal uptake within the head of the pancreas, consistent with a pancreatic neuroendocrine tumor. Pathological examination did not reveal any malignancy within the pancreas. Instead, the pancreatic head showed pancreatic polypeptide cell hyperplasia. Strong and diffuse immunoreactivity to somatostatin receptor 2A antibody by immunoperoxidase staining confirmed that the lesion correlated with the site of radioactive tracer (Indium-111 pentetreotide) uptake seen on SRS. The current report therefore presents pancreatic polypeptide cell hyperplasia as a new pitfall in SRS.