Clinical Impact of Endoscopic Ultrasound-Guided Fine-Needle Biopsy in Radiologically Suspected Pancreatic Neuroendocrine Tumors.

OBJECTIVES: Incidental diagnosis of pancreatic neuroendocrine tumors (PNETs) is increasing. Its surgical indication depends on the risk of progression, whereas histological features can be assessed by endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). However, its systematic use remains a matter of debate. We aimed to analyze the impact of EUS-FNB on therapeutic management in patients with radiologically suspected PNETs. METHODS: In this retrospective observational single-center study, all patients with suspected PNET by radiological imaging who underwent EUS-FNB from 2011 to 2023 were enrolled. Patients with multiple endocrine neoplasia or previous/metastatic tumors were excluded. The North American Neuroendocrine Tumor Society (NANETS) consensus was followed, and modifications in management due to FNB findings were detailed. RESULTS: Of 212 patients undergoing EUS-FNB for suspected PNETs, 146 patients were included. No severe adverse events were reported during the biopsy procedure. Surgical pathology showed that the median tumor size was 17 mm, 32.2% were located in the pancreatic head. Therapeutic management was modified in 12 (8.2%) patients based on EUS-FNB findings due to different tumor types or additional high-risk tumor feature (n = 5), different tumor grading (n = 4), and absence of malignancy (n = 3). CONCLUSION: Systematic EUS-FNB improves accuracy in PNET diagnosis and is associated with a non-negligible rate of change in management. Large-scale studies are needed to confirm our findings.