Diagnostic Endoscopic Ultrasound in Pancreatology: Focus on Normal Variants and Pancreatic Masses

Abstract

Background: Endoscopic ultrasound (EUS) is a main tool in gastroenterology for both diagnosis and exclusion of pancreatic pathology. It allows minimally invasive assessment of various diseases or anatomic variations affecting the pancreas also with the help of new Doppler technologies, elastography, contrast-enhanced imaging including post hoc image processing with quantification analyses, three-dimensional reconstruction, and artificial intelligence. EUS also allows interventional direct access to the pancreatic parenchyma and the retroperitoneal space, to the pancreatic duct, pancreatic masses, cysts, and vascular structures.

Summary: This review aimed to summarize new developments of EUS in the field of pancreatology. We highlight the role of EUS in evaluating pancreatic pathology by describing normal anatomic variants like pancreas divisum, pancreatic lipomatosis, pancreatic fibrosis in the elderly and characterizing pancreatic masses, both in the context of chronic pancreatitis and within healthy pancreatic parenchyma. EUS is considered the optimal imaging modality for pancreatic masses of uncertain dignity and allows both cytological diagnosis and histology, which is essential not only for neoplastic conditions but also for tailoring therapy for benign inflammatory conditions.

Key messages: EUS plays an indispensable role in pancreatology and the development of new diagnostic and interventional approaches to the retroperitoneal space and the pancreas exponentially increased over the last years. The development of computer-aided diagnosis and artificial intelligence algorithms hold the potential to overcome the obstacles associated with interobserver variability and will most likely support decision-making in the management of pancreatic disease.

Keywords: Contrast-enhanced endoscopic ultrasound; Elastometry; Endoscopic ultrasound; Pancreatic cancer; Pancreatitis.

Fig. 1.

Visualization of the different echogenicity between the hypoechoic ventral split (*) and the hyperechoic lipomatotic pancreatic head (X) with linear EUS.

Fig. 2.

Pancreas lipomatosis. EUS showing the pancreas body from gastric position with a regular not dilated pancreatic duct. Increased echogenicity of the pancreatic parenchyma compared to the kidney (*) defines pancreatic FI or lipomatosis.

Fig. 3.

EUS of the papillary region with normal anatomical visualization of the stack sign (CBD, common bile duct; PD, pancreatic duct; PV, portal vein).

Fig. 4.

EUS of a PD with calcifying chronic pancreatitis. EUS diagnosis is supported by the lack of the stack sign (CBD, common bile duct; PD, pancreatic duct; PV, portal vein; *calcification).

Fig. 5.

Example of a pancreas in elderly patients. The pancreatic duct (1) is irregular with slight proximal dilation without an obstructive cause. The pancreatic parenchyma shows hyperechoic foci which correspond to fibrosis (*). Other hyperechoic spots correspond histologically to FI, which can be diffuse (see Fig. 2) or focal.

Fig. 6.

EUS in the transgastric position showing an autoimmune pancreatitis before steroid therapy. The pancreatic body is “sausage”-like enlarged with hypoechoic areas. The main pancreatic duct (1) is not dilated with hyperechoic borders.