Detection of recurrent pancreatic primitive neuroectodermal tumor by tc-99m hydrazinonicotinyl-tyr3-octreotide scan.

A 24-year-old asymptomatic female with a history of exophytic primitive neuroectodermal tumor in the uncinate process of the pancreas was evaluated by Tc-99m hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC) imaging as a part of the routine check-up. The images revealed focally increased activity in the head of the pancreas, indicating possible recurrent tumor. However, the results of all examinations considered, especially because of negative results from anatomic imaging, the finding from the HYNIC-TOC scan was regarded as likely false positive, and no new actions were taken. Eighteen months later, the patient developed abdominal mass. Repeat HYNIC-TOC imaging redemonstrated the focus of abnormal activity, which was confirmed as recurrent primitive neuroectodermal tumor pathologically.