EUS-Guided Trucut Biopsy adds Significant Information to EUS-Guided FNA in Selected Patients: A Prospective Study

Background: EUS-guided Trucut biopsy (EUS-TCB) has recently emerged as a method that tries to overcome the limitations of EUS-guided fine needle aspiration (EUS-FNA) by providing a core-tissue specimen needed to increase the yield and accuracy of diagnosis. Methods: The aim of our study was to evaluate whether EUS-TCB adds any information to EUS-FNA, in selected patients, and to assess the diagnostic yield, overall accuracy and complications of EUS-TCB as compared with EUS-FNA. The study included prospectively 30 patients which un-derwent both procedures. Results: The yield of adequate tissue harvesting was similar for EUS-FNA and EUS-TCB (96.4% versus 89.3%, P=NS), with the same number of passes done. The diagnostic accuracy of EUS-FNA was also similar with that of EUS-TCB for the diagnosis of malignant mediastinal masses (73.7% versus 68.4%, P=NS). However, the accuracy for obtaining a specific diagnosis was significantly lower for EUS-FNA as compared with EUS-TCB (5.3% and 68.4%, P<0.005). EUS-TCB did not appear to help as a rescue procedure in mediastinal tumors, after a false negative result of EUS-FNA. All cases of submucosal tumors were correctly classified by EUS-TCB as GIST or leiomyo-mas, while EUS-FNA raised only a suspicion of mesenchymal tumor. Conclusion: EUS-TCB was certainly useful when immunohistochemistry was needed, for e.g. in submucosal tumors and lymphoma, as well as to confirm and characterize the primary or metastatic origin of mediastinal masses. The information provided by EUS-FNA and EUS-TCB are comple-mentary, especially in selected cases where a complete histological diagnosis has an important im-pact on the clinical management.