Contrast harmonic endoscopic ultrasonography in the characterization of pancreatic metastases (with video).

Objectives: The differential diagnosis between primary pancreatic neoplasms vs. pancreatic metastases (PM) is challenging. Endoscopic ultrasonography with fine needle aspiration (EUS-FNA) can be used to differentiate primary vs. metastatic tumours, although with a suboptimal accuracy. Recently, contrast harmonic EUS (CH-EUS) has been reported as an adjunct in the diagnosis of pancreatic neoplasms. We evaluated the potential role of CH-EUS in the differential diagnosis of PM. Methods: Retrospective analysis of a prospectively maintained database. Out of 266 patients, 4.1% were diagnosed with PM. EUS-FNA and/or surgical pathology represented our gold standard. Results: The origin of PM was: renal cancer (3), colon cancer (2), breast cancer (2), ovarian cancer (1), melanoma (1), lymphoma (1), sarcoma (1). All lesions appeared hypoechoic at standard EUS. At CH-EUS, 6/11 lesions appeared hypoenhancing (colon cancer, sarcoma, breast and ovarian cancer), 4/11 were hyperenhancing (renal cancer and lymphoma ), and 1/11 isoenhancing (melanoma). Conclusions: In our population, standard EUS features of PM were unremarkable. At CH-EUS, the majority of PM appeared hypoenhancing suggesting a possible malignant origin. However, a subset of PM showed hyperenhancing pattern. In the appropriate context, particularly when cancer history is present, CH-EUS may add to the differential diagnosis and potentially spare EUS-FNA.