Evaluation of renal lesions using contrast-enhanced ultrasound (CEUS); a 10-year retrospective European single-centre analysis

Objective To investigate the usefulness of contrast-enhanced ultrasound (CEUS) in the evaluation of renal masses. Methods This study included 255 patients with renal masses. Ages ranged from 18-86 years. CEUS was used for determining malignancy or benignancy and findings were correlated with the histopathological outcome. Out of 255 lesions, 212 lesions were malignant (83.1%) and 43 were benign (16.9%). Diagnostic accuracy was tested using the histopathological diagnosis as the gold standard. Results CEUS showed a sensitivity of 99.1% [95% confidence interval (CI): 96.7%, 99.9%], a specificity of 80.5% (CI: 65.1%, 91.2%), a positive predictive value of 96.4% (CI: 93.0%, 98.4%) and a negative predictive value of 94.3% (CI: 80.8%, 99.3%). Kappa for diagnostic accuracy was kappa = 0.85 (CI: 0.75, 0.94). Of 212 malignant lesions, 200 renal cell carcinomas and 12 other malignant lesions were diagnosed. Out of 43 benign lesions, 10 angiomyolipomas, 3 oncocytomas, 8 renal cysts and 22 other benign lesions were diagnosed. Conclusion CEUS is an useful method to differentiate between malignant and benignant renal lesions. To date, to our knowledge, this is the largest study in Europe for the evaluation of renal lesions using CEUS with a histopathological validation.