Contrast-Enhanced Ultrasound (CEUS) for the Evaluation of Bosniak III Complex Renal Cystic Lesions—A 10-Year Specialized European Single-Center Experience with Histopathological Validation

Abstract

Background and objectives: The aim of the present retrospective single-center study is to evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) for assessing Bosniak III complex renal cystic lesions with histopathological validation. Materials and Methods: 49 patients with CEUS-categorized Bosniak III renal cystic lesions were included in this retrospective study. All patients underwent native B-mode, Color Doppler, contrast-enhanced ultrasound (CEUS) between 2010–2020. Eight and five patients underwent computed tomography (CT) and magnetic resonance imaging (MRI), respectively. Twenty-nine underwent (partial) nephrectomy allowing for histopathological analysis. The applied contrast agent for CEUS was a second-generation blood pool agent. Ultrasonography examinations were performed and interpreted by a single experienced radiologist with more than 15 years of experience (EFSUMB Level 3). Results: CEUS examinations were successfully performed in all included patients without registering any adverse effects. The malignancy rate of CEUS-categorized Bosniak III renal lesions accounted for 66%. Initially, cystic complexity was visualized in native B-mode. In none of the renal lesions hypervascularization was detected in Color Doppler. CEUS allowed for detection of contrast enhancement patterns in all included Bosniak III renal lesions. Delayed wash-out could be detected in 6/29 renal lesions. In two cases of histopathologically confirmed clear-cell RCC, appropriate up-grading from Bosniak IIF to III was achieved by CEUS. Conclusions: CEUS depicts a promising imaging modality for the precise diagnostic workup and stratification of renal cystic lesions according to the Bosniak classification system, thereby helping guidance of adequate clinical management in the future.

Role of contrast-enhanced ultrasound in assessing indeterminate renal lesions and Bosniak ≥2F complex renal cysts found incidentally on CT or MRI

“…Findings initially assessed as 2F by CT and/or MRI were the main object of reclassification among CRC, which occurred in 72.2% of assignments, either on the side of downgrading or upgrading (52.8 and 46.2% of the reclassified cases, respectively). This is in accordance with previous results by Schwarze et al, 19 and matches with the expectedly high sensitivity of CEUS we observed. 13,20–22 The reclassification rate we found in the CRC group was higher compared to what previously shown (10–20%).…”

SERS Liquid Biopsy Profiling of Serum for the Diagnosis of Kidney Cancer

“…In the case of Bosniak III cysts, which are defined as indeterminate cystic masses with thickened irregular walls or septa with enhancement and which have an approximately 50% chance of being malignant [ 9 ], partial or radical nephrectomy is warranted. Existing non-invasive methods of reducing the number of unnecessary nephrectomies are suboptimal, as highlighted by a recent study evaluating contrast-enhanced ultrasonography (CEUS), which reported that only 63% of CEUS-diagnosed Bosniak III cysts were malignant after partial or radical nephrectomy [ 36 ]. Whether SERS is also able to differentiate between benign and malignant cystic lesions is currently unknown and will require future studies.…”

Prospective Comparison of Contrast-Enhanced Ultrasound and Magnetic Resonance Imaging to Computer Tomography for the Evaluation of Complex Cystic Renal Lesions

“…In this study, CEUS had a sensitivity of 100% and a NPV of 100 %, but it has the limitation that the results are dependent on the observer's previous CEUS experience. [24][25][26][27] Since standardized and specific molecular imaging-related criteria for CEUS are lacking, the reproducibly of the Bosniak classification using this technique is dependent on the experience and criteria applied by the on-site ultrasonographer. 28 In the present study, renal CEUS examinations were performed or supervised by a single skilled nephrologist (SA) with more than 20 years of clinical experience in renal ultrasound and more than 10 years CEUS experience in transplanted or native kidneys.…”