Sa1505 Incremental Value of EUS-FNA Compared With CT/MRI in the Management of Pancreatic Neuroendocrine Tumors (pNETs): Defining the Pivotal Role of EUS-FNA

Abstract

Incremental Value of EUS-FNA Compared With CT/MRI in the Management of Pancreatic Neuroendocrine Tumors (pNETs): Defining the Pivotal Role of EUS-FNA Justin A. Reynolds*, Alireza Sedarat, Irma Oliva, Sergei Tatishchev, Joseph R. Pisegna, James J. Farrell Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA; Department of Pathology, David Geffen School of Medicine at UCLA, Los Angeles, CA; Division of Gastroenterology and Hepatology, VA Greater Los Angeles Healthcare System, Los Angeles, CA Background: Pancreatic neuroendocrine tumors (PNETs) are rare but are increasingly being identified in patients due to greater awareness and improved imaging modalities. Endoscopic ultrasound (EUS) with fine needle aspiration (FNA) allows for highly sensitive and specific localization and diagnosis of PNETs. However, the role of EUS-FNA in the pre-operative staging of PNETs is not clearly defined. Accordingly, the current study was undertaken to investigate the impact of EUS-FNA on the surgical management of patients with newly diagnosed PNETs. Methods: We reviewed a clinical-pathology database of all pancreatic specimens at the UCLA Medical Center from January 1999 through October 2011 that included neuroendocrine tumor, neoplasm, or carcinoma, including all patients who underwent EUS-guided FNA. Patient demographics, clinical presentation, indication for EUS-FNA, and possible impact on surgical management were assessed. Results: 80 patients (mean age 57 16 years, 55% male) were identified with PNETs by EUS-FNA. Mean tumor size by EUS was 20.8mm 16.3mm (range 4-70mm). Tumor locations in the pancreas included the head/neck (43), body/tail (35), or multifocal (2). EUS-FNA diagnosing PNET impacted on the surgical management of 40 patients by: (a) finding resectable PNET incidentally despite negative CT or MRI imaging (19); (b) confirming the diagnosis of PNET in patients previously suspected as having lymphoma or metastases (8); (c) confirming PNET in the setting of a pancreatic cyst (2); (d) precluding surgery for PNET by finding vascular invasion or metastases not seen on MRI or CT (3); and (e) helping medical decision-making favoring observation rather than surgery because of patient comorbidities and the likelihood of slower tumor progression (8). Conclusions: EUS-FNA affects the surgical management of PNETs by identifying resectable tumors not seen by CT or MRI, identifying PNETs in patients previously suspected as having lymphoma or metastases, and by identifying metastatic disease not seen by CT or MRI. The finding of PNET on EUS-FNA also leads some patients to observation rather than surgery because of comorbidities and the expected slow progression of disease, while offering the potential for use of newer chemotherapeutic agents (e.g. sunitinib, everolimus) in patients with unresectable disease. Further efforts to expand on the role of EUS in the management and surveillance of PNETs should be pursued.