Islet cell tumors of the pancreas are rare, having an estimated prevalence of 10 per 1 million persons. After biochemical evidence in support of an islet cell tumor is obtained, various strategies are employed to localize the tumor so that definitive surgical resection can be attempted. The purpose of this study was to demonstrate the role of EUS and EUS guided FNA in localization and management of pancreatic endocrine tumors. Methods: The EUS databases of 3 medical centers (2 University-IUMC, MUSC; and 1 community based -St. Vincent's) from 1993 to 1996 were reviewed. Patients who had undergone EUS guided FNA for the diagnosis, localization and staging of suspected pancreatic neuroendocrine tumors were analyzed. Results: Fourteen patients with suspected islet cell tumors were identified. Five patients had multifocal lesions on EUS. EUS-guided FNA was performed in all patients; 2 patients had FNA suspicious for gastrinoma but were chromogranin negative on immunostaining; 1 FNA of a suspected gastrinoma was completely negative on cytologic review. One patient with a suspected multifocal insulinoma (2 lesions) had a tail lesion confirmed to be a reactive lymph node by FNA. EUS guided FNA cytology reduced the false positive rate of EUS from 29% (4 of 14 patients) to 0%. In the five patients with hormonally active tumors, the addition of FNA changed the operative approach in 2 patients with multifocal lesions seen at the time of EUS. In the 6 patients with nonfunctional islet cell tumors, FNA prompted debulking surgery for unresectable neuroendocrine tumors. The sensitivity of computerized tomography for islet cell tumor (functional and nonfunctional) localization was 60%. There were no complications. Conclusions: 1.) Addition of FNA to EUS in patients with suspected islet cell tumors is safe and significantly lowers the false positive rate. 2.) Indications for FNA with EUS include multifocal pancreatic lesions or equivocal biochemical results. 3.) The added information obtained by EUS-FNA can be used by the surgeon to plan the optimal management strategy for a given patient.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging