Superb Microvascular Imaging (SMI) and Two-Dimensional Endoscopic Ultrasound Guided Shear Wave Elastography (2D-SWE-EUS) in Differential Diagnosis of Pancreatic Adenocarcinoma (PA) From Other Pancreatic Solid Lesions (PSLs) and Pancreatic neuroendocrinE Tumors (pNETs) Malignancy

Pancreatic adenocarcinoma (PA) is the most common tumor of the pancreas. Given its poor prognosis and the major therapeutic consequences, the discrimination between PA and other pancreatic solid lesions is mandatory. Endoscopic ultrasound (EUS) is admitted as the most sensitive imaging procedure for the detection and characterization of pancreatic tumors. Over the past 30 years, EUS-guided tissue acquisition (EUS-TA), or more recently fine needle biopsy (EUS-FNB), has demonstrated its efficiency for tissue sampling and remains the gold standard for the pathologic diagnosis of pancreatic lesions. The assessment of pancreatic tumor enhancement using ultrasound contrast agents (UCAs) in real time with imaging specific methods seems useful to improve their characterization either by contrast-enhanced EUS (CE-EUS) or, more recently, by contrast-harmonic EUS (CH-EUS). CH-EUS was already demonstrated useful to differentiate pancreatic adenocarcinoma from other pancreatic lesions. EUS-Elastography (EUS-E) is another EUS image enhancement technique, which rational based on the difference in elasticity between the tissues. There are two types of elastographies: strain elastography (SE) and shear wave elastography (SWE). SE has proved useful for the characterization of pancreatic lesions and lymph nodes. However, this technique was demonstrated difficult to perform with adequate accuracy and reproducibility for pancreatic lesions and have many limitations. In some recent publications SWE was demonstrated moderate reliability. Pancreatic neuroendocrine tumors (pNETs) are rare tumors, but according to the last epidemiological data, their incidence and prevalence are steadily rising. Surgical resection is generally performed for pNETs due to their malignant potential. However, with increasing use of high-resolution conventional imaging, the significant incidence of small (≤ 2 cm) pancreatic neuroendocrine incidentaloma (pNET) has risen in recent decades. EUS is recognized a