Abstract
Pancreatic neoplasms are derived from epithelial and nonepithelial elements and classified into two categories: solid and cystic tumors. The solid epithelial tumor includes ductal cell carcinomas, acinar cell carcinomas, and islet cell tumors. On the other hand, cystic epithelial tumors include serous cystic neoplasms (SCN), mucinous cystic neoplasms (MCN), and intraductal papillary mucinous tumors (IPMT). Ultrasonography is one of the most noninvasive and less-expensive modalities for detecting a pancreatic mass and characterizing the tumor tissue. Additionally, color Doppler imaging is very sensitive to arterial blood flow, making it valuable for differentiating islet cell tumors from ductal carcinomas. Contrast-enhanced ultrasonography (CEUS) is also useful for estimating a small amount of blood flow into hypovascular tumors; therefore, differential diagnosis of islet tumors or inflammatory pseudotumors from ductal cancer is possible. Moreover, CEUS is efficient for assessing the volume of mural nodule or tumor projection in a cystic lesion, which is thought to be important for us to choose therapeutic strategies. Endoscopic ultrasonography (EUS) is the most efficacious tool for establishing definite diagnosis of a solid mass as well as prediction of tumor expansion of a carcinoma. IDUS is also useful for evaluating minimal invasion of intraductal papillary-mucinous adenocarcinomas (IPMC). Recently, endoscopic ultrasound-guided fine needle aspiration biopsy (FNA) is recommended to obtain pathological proof of an uncertain nodule.
