Comments on and Illustrations of the EFSUMB CEUS Guidelines: Transabdominal and Endoscopic Ultrasound Features of Intrapancreatic Metastases and the Role of Multiparametric Imaging and EUS-Guided Sampling in Rare Pancreatic Tumors

Intrapancreatic metastases are rare. They could occur at the same time or years later after the initial diagnosis of the tumor. Sonography and endosonography with contrast enhanced techniques provide very good additional information for differential diagnosis from other tumors. The most common solitary metastasis is that of renal cell carcinoma, with good prognosis after surgical resection. The further procedure, and in other tumor entities, depends on the primary tumor. This requires confirmation by endosonographic guided sampling, with the collection of material for immunohistological examination.Abstract: A definite pathologic diagnosis of intrapancreatic metastasis is crucial for the management decision, i.e., curative or palliative surgery versus chemotherapy or conservative/palliative therapy. This review focuses on the appearance of intrapancreatic metastases on native and contrast-enhanced transabdominal ultrasound and endoscopic ultrasound. Differences and similarities in relation to the primary tumor, and the differential diagnosis from pancreatic carcinoma and neuroendocrine neoplasms are described. The frequency of intrapancreatic metastases in autopsy studies and surgical resection studies will be discussed. Further emphasis is placed on endoscopic ultrasound-guided sampling to confirm the diagnosis.