Diagnostic and Interventional Role of Endoscopic Ultrasonography for the Management of Pancreatic Neuroendocrine Neoplasms

Abstract

Pancreatic neuroendocrine neoplasms (PanNENs) are relatively rare, but their incidence has increased significantly in the last decades. Precise diagnosis and prognostic stratification are crucial for proper patient management. Endoscopic ultrasound (EUS) is the modality of choice for diagnosis of solid pancreatic tumors, showing a higher tumor detection rate than other imaging modalities, especially for small size lesions. EUS also serves as a guide for preoperative sampling and other interventions. EUS-tissue acquisition is a safe and highly accurate technique for cyto/histological diagnosis of PanNENs with a well-demonstrated correlation between Ki-67 proliferation index values and tumor grading on EUS and surgical specimens according to the WHO 2017 classification. Furthermore, the possibility of a preoperative EUS-guided fine needle tattooing or fiducial markers placement may help the surgeon to locate small and deep tumors, thus avoiding formal pancreatic resections in favor of parenchymal-sparing surgery. Finally, locoregional ablative treatments using either ethanol injection or radiofrequency ablation have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients unfit for surgery with functioning or non-functioning PanNENs. This article review highlights the current role of EUS in PanNENs management, focusing on the present and future applications of EUS-guided interventions.

A Single-center Prospective Observational Study Investigating the Accuracy of Preoperative Diagnostic Procedures in the Assessment of Lymph Node Metastases in Nonfunctioning Pancreatic Neuroendocrine Tumors

“…CE-CT is the best imaging modality for staging the primary tumor because of the characterization of vascular involvement whereas 68 Ga-DOTA-peptides PET is the most accurate procedure for detecting metastatic disease 9,11. Endoscopic ultrasound (EUS) plays also a central role in the diagnosis of NF-PanNETs as it can provide additional information such as the distance between the tumor and the main pancreatic duct as well as the Ki67 proliferative index through fine-needle aspiration/biopsy 10. Therefore, current guidelines recommend the use of CE-CT, EUS, and 68 Ga-DOTA-peptides PET as first-line diagnostic imaging methods to evaluate and stage the extent of disease 6,7.…”

Nonfunctional pancreatic neuroendocrine tumours misdiagnosed as autoimmune pancreatitis: A case report and review of literature

“…EUS-FNA/FNB not only has higher sensitivity for PNETs but also detects lesions ranging from 4 cm to 10 cm[ 34 , 42 ] and provides additional information ( e.g. , distance from the main pancreatic duct and the Ki-67 proliferation index) for proper therapeutic management[ 43 ].…”

Endoscopic techniques for diagnosis and treatment of gastro-entero-pancreatic neuroendocrine neoplasms: Where we are

“…The incidentally discovered small panNENs, mainly nonfunctional, represent a therapeutic challenge because surgery could be very complex in the face of neoplasms with indolent biological behavior, and active surveillance may represent an option for G1 or low G2 neoplasms, asymptomatic, mainly localized in the head of the pancreas, without radiological signs suspicious for malignancy[ 8 , 75 ]. In this setting, however, EUS-guided pancreatic locoregional ablative treatments, using either ethanol injection or radiofrequency ablation, have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients[ 76 ]. The thermoablative techniques are the most used, mainly the radiofrequency methods.…”