Contrast-enhanced ultrasonography (CEUS) in the evaluation of pancreatic masses compared with histology of ultrasound (US)-guided percutaneous biopsy

Abstract

Purpose: This study aimed to assess the role of CEUS in the evaluation of pancreatic masses. Material and methods: 78 patients underwent CEUS from 2008 to 2012. Lesion was located in pancreatic head in 36 cases, in pancreatic body and tail respectively in 23 and 19 cases. Vascular pattern of pancreatic lesions was evaluated during arterial phase of contrast distribution. CEUS-based diagnosis was compared with histological evaluation of biopsy specimens obtained by US-guided percutaneous biopsy (66 cases), endosonography (EUS)-guided biopsy (4 cases) and surgery (8 cases). Results: Final histological diagnosis was the following: ductal adenocarcinoma in 60 cases, neuroendocrine tumor in 9 cases, pancreatic non-Hodgkin lymphoma in 2 cases, metastasis from kidney and breast cancers in 2 cases, serous and mucinous cystic tumors in 4 cases and pancreatic pseudocyst in one case. Hypovascular pattern during arterial phase, characteristic of pancreatic carcinoma, was observed in 58/60 cases of ductal adenocarcinoma, with 2 false negative results. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA) of hypovascular pattern for diagnosis of adenocarcinoma were respectively 96%, 100%, 100%, 90%, 97%. Hypervascular pattern during arterial phase was characteristically observed in all cases of neuroendocrine tumors, with 6 false positive results in 2 cases of ductal adenocarcinoma, 2 cases of metastasis and 2 cases of non-Hodgkin lymphoma. Sensitivity, specificity, PPV, NPV and DA of hypervascular pattern for neuroendocrine masses were respectively 100%, 92%, 60%, 100% and 92%. Cystic lesions were correctly identified by CEUS but no different pattern of vascularization between serous and mucinous lesions was observed. Also pseudocysts were correctly identified by CEUS. We observed no complications following CEUS, US and EUS-guided biopsies. Conclusion: CEUS allows detection and characterization of pancreatic masses, better than US. It is an effective procedure in pancreatic imaging and avoids more invasive procedures.