EFSUMB 2020 Proposal for a Contrast-Enhanced Ultrasound-Adapted Bosniak Cyst Categorization - Position Statement.

The well-established Bosniak renal cyst classification is based on contrast-enhanced computed tomography determining the malignant potential of cystic renal lesions. Ultrasound has not been incorporated into this pathway. However, the development of ultrasound contrast agents coupled with the superior resolution of ultrasound makes it possible to redefine the imaging of cystic renal lesions. In this position statement, an EFSUMB Expert Task Force reviews, analyzes, and describes the accumulated knowledge and limitations and presents the current position on the use of ultrasound contrast agents in the evaluation of cystic renal lesions.

Prospective comparison of use of contrast-enhanced ultrasound and contrast-enhanced computed tomography in the Bosniak classification of complex renal cysts.

AIM: To compare contrast-enhanced ultrasound and contrast-enhanced computed tomography in the evaluation of complex renal cysts using the Bosniak classification. METHODS: Forty-six patients with 51 complex renal cysts were prospectively examined using contrast-enhanced ultrasound and contrast-enhanced computed tomography and images analysed by two observers using the Bosniak classification. Adverse effects and patients' preference were assessed for both modalities. RESULTS: There was complete agreement in Bosniak classification between both modalities and both observers in six cysts (11.8%). There was agreement of Bosniak classification on both modalities in 21 of 51 cysts (41.2%) for observer 1 and in 17 of 51 cysts (33.3%) for observer 2. Contrast-enhanced ultrasound gave a higher Bosniak classification than corresponding contrast-enhanced computed tomography in 31 % of cysts by both observers. Histological correlation was available in three lesions, all of which were malignant and classified as such simultaneously on both modalities by at least one observer, with remaining patients followed up with US or CT for 6-24 months. No adverse or side effects were reported following the use of US contrast, whilst 63.6% of patients suffered minor side effects following the use of CT contrast. 81.8% of the surveyed patients preferred contrast-enhanced ultrasound to contrast-enhanced computed tomography. CONCLUSION: Contrast-enhanced ultrasound is a feasible tool in the evaluation of complex renal cysts in a non-specialist setting. Increased contrast-enhanced ultrasound sensitivity to enhancement compared to contrast-enhanced computed tomography, resulting in upgrading the Bosniak classification on contrast-enhanced ultrasound, has played a role in at best moderate agreement recorded by the observers with limited experience, but this would be overcome as the experience grows. To this end, we propose a standardised proforma for the contrast-enhanced ultrasound report. The benefits of contrast-enhanced ultrasound over contrast-enhanced computed tomography include patients' preference and avoidance of ionising radiation or nephrotoxicity, as well as lower cost.

Growth rate and malignant potential of small gallbladder polyps--systematic review of evidence.

THE BACKGROUND AND PURPOSE: The overall aim of this systematic review was to determine whether ultrasound (US) follow up for gallbladder polyps (GBPs) measuring less than 10 mms is necessary. METHODS: A search was performed in MEDLINE and EMBASE between January 1976 and January 2012 using keywords: gallbladder, polyps, neoplasm, cancer, tumour, carcinoma, malignant, adenoma. Included were studies involving adult patients, examined with transabdominal US at least twice. The outcomes of included studies were gallbladder polyp growth as demonstrated on US over time, followed where available by histological examination of cholecystectomy specimens. MAIN FINDINGS: Ten studies met the inclusion criteria for the review. Altogether 1958 subjects with mean age between 41.5 and 59 years were followed up with US. The percentage of GBPs which showed growth over the follow up period ranged from 1% to 23%. 43 neoplastic polyps were found in total irrespective of size, 20 of which were malignant and at least 7 of those were >10 mms. At least 7 malignancies were present in polyps <10 mms but it was unknown if they had undergone growth on follow up. CONCLUSIONS: Level II-2 and below evidence on rate of growth of small GBPs <10 mms exists in the literature. It indicates that growth does occur in a significant minority of small GBPs, but it is slow. Due to deficient reporting and small numbers of cases, the correlation between growth of GBP and development of malignancy cannot be established using currently available evidence. Malignancy can be present in polyps <10 mms although it is significantly more frequent in polyps >10 mms. Cholecystectomy for symptomatic GBPs irrespective of their size, alongside the current practice for removal of gall bladders containing asymptomatic polyps >10 mms, is proposed. No evidence based US follow up schedule can be recommended at present for asymptomatic polyps <10 mms, and in its absence an intuitive follow up with US is likely to continue.