EUS for pancreatic neuroendocrine tumors: a single-center, 11-year experience

Background: Pancreatic neuroendocrine tumors (PNTs) are rare tumors with malignant potential. PUS and EUS-guided FNA (EUS-FNA) have been shown to he superior to other imaging methods in the preoperative localization and diagnosis of PNTs. Objectives: To evaluate the clinical presentation, EUS morphology, and sensitivity of EUS-FNA cytology in a large consecutive cohort with histologically and/or cytologically confirmed PNTs. Design: Retrospective study of all consecutive patients from July 1995 to November 2006 who underwent EUS for a known or suspected PNT and had a subsequently histologically confirmed PNT. Setting: Tertiary referral center. Patients: Ninety-two patients with suspected PNT. Interventions: EUS evaluation with or without EUS-FNA of PNTs. Main Outcome Measurements: Clinical and EUS features of PNTs and sensitivity of EUS-FNA for the diagnosis of PNTs. Results: Ninety-two patients underwent EUS; 76 patients had confirmed histopathology, of whom 69 (91%) were symptomatic. Patients with functional PNTs presented with diarrhea, peptic ulcer disease, and hypoglycemia. Tumor locations and echogenic features were similar except that nonfunctional PNTs tended to be larger and have cystic features. Patients with malignant PNTs were older (P = .03), presented with abdominal pain, and had larger tumors (P = .0006) with irregular margins. Eighty-nine percent of patients underwent EUS-FNA. Sensitivity of EUS-FNA for the diagnosis of a PNT was 87%. Sensitivity of EUS-FNA was similar in functional and nonfunctional PNTs. The sensitivity of EUS-FNA was higher for malignant PNTs (P = .008). Limitations: Retrospective single tertiary center. Conclusions: EUS and EUS-FNA are sensitive tools, especially in cases of suspected symptomatic PNTs in which other imaging modalities have failed. (Gastrointest Endosc 2010;71:1185-93)