Focal Pancreatitis Mimicking Neuroendocrine Tumor on DOTATATE PET/CT With Radiology-Pathology Correlation

A 54-year-old man presented with left lower quadrant pain. CT showed no cause for his pain but identified an incidental 2.0-cm enhancing lesion in the pancreatic tail. On MRI, this lesion was hyperenhancing and diffusion-restricting, suspicious for a neuroendocrine tumor. However, EUS-guided biopsy yielded only benign pancreatic tissue. Due to this discordance, 64 Cu-DOTATATE PET/CT was performed. The pancreatic tail lesion was tracer-avid, suggesting a well-differentiated neuroendocrine tumor. Based on the PET findings, the patient underwent distal pancreatectomy. Surgical pathology revealed only focal chronic pancreatitis with islet aggregation, a previously undescribed mimic of neuroendocrine tumor on DOTATATE PET/CT.