Cystic Renal Lesions Research Articles

Increased prevalence of renal cysts in patients with sickle cell disease

BackgroundEarly detection and interventions have enabled patients with sickle cell disease (SCD) to live well into adulthood. Consequently, the chronicity of SCD allows for the insidious manifestation of multisystem complications, including renal damage. Cystic renal lesions are commonly incidentally discovered on ultrasound and computerised tomography (CT) imaging of the abdomen. Most are benign simple cysts, however, difficulties may be encountered if infection, rupture, haemorrhage or cancerous changes develop. We aimed to determine whether patients with SCD have a higher prevalence of simple renal cysts compared to non-SCD individuals.MethodsData for a group of 223 patients with SCD who had undergone an ultrasound and/or CT imaging of the abdomen were extracted for comparison with 180 control patients (haemoglobin genotype unknown), matched for age and ethnicity. Scans were evaluated for 198 SCD patients and 180 controls.ResultsRenal cysts were found in 58% of the SCD group and 20% of the controls (OR 5.4 (CI 2.6–11.0), RR 2.8 (CI 1.9–4.2)). Bilateral renal cysts were found in 28% of the SCD participants in comparison with 5% of the control group. In those who had one or more cysts identified, the average number of cysts was 3.76 for the SCD group and 1.94 for the controls. Men with SCD were more likely to develop cysts than women (66% vs 53%), as were men without SCD (22% vs 17%).ConclusionsSimple renal cysts occur more frequently, are more abundant and develop at a younger age in patients with SCD than ethnically-matched controls. Further study of the mechanism underlying cyst formation may shed light on both sickle cell nephropathy and other cystic renal diseases.

Ultrasound Imaging of Cystic Nephroma.

Cystic nephroma is a rare, benign multicystic lesion of the kidney. This tumor occurs both in children and in adults. In children, it is highly prevalent in males; in adults, it is more frequent in women. The term “cystic nephroma” represents two apparently different entities: pediatric cystic nephroma, a benign form thought to originate from metanephric tissue, and adult cystic nephroma, considered as a lesion of mixed epithelial stromal tumor. The clinical presentation may be a palpable mass or nonspecific symptoms such as abdominal pain, hematuria, and urinary tract infections. In this review, we summarize the ultrasound imaging features of cystic nephroma and describe the characteristics of the most common renal cystic lesions and the differential diagnosis of cystic nephroma with other renal cystic lesions.

Hereditary Renal Cystic Disorders: Imaging of the Kidneys and Beyond.

The purpose of this article is to review the hereditary renal cystic diseases that can manifest in children and adults, with specific attention to pathogenesis and imaging features. Various common and uncommon hereditary renal cystic diseases are reviewed in terms of their underlying etiology, including the involved genetic mutations and the affected proteins and cellular structures. Focus is placed on the morphologic findings in each condition and the features that distinguish one disorder from another. The two most common categories of hereditary renal cystic disease are (a) the ciliopathic disorders, which are related to mutations affecting the primary cilia (called "ciliopathies"), and (b) the phakomatoses. Autosomal dominant polycystic kidney disease, autosomal recessive polycystic kidney disease, and the "medullary cystic disease complex" are all ciliopathies but have different phenotypes. Tuberous sclerosis complex and the associated "contiguous gene syndrome," as well as von Hippel-Lindau syndrome, are phakomatoses that can manifest with cystic renal lesions but have uniquely different extrarenal manifestations. Finally, DICER1 mutations can manifest with renal cystic lesions (typically, cystic nephromas) in patients predisposed to other malignancies in the chest, ovaries, and thyroid. Although some overlap exists in the appearance of the renal cysts associated with each of these diseases, there are clear morphologic differences (eg, cyst size, location, and complexity) that are emphasized in this review. To improve patient outcomes, it is important for the radiologist to recognize the various hereditary renal cystic diseases so that a correct diagnosis is assigned and so that the patient is adequately evaluated and followed up. ©RSNA, 2017.

MP100-07 COMPARISON OF ONCOLOGIC RESULTS, FUNCTIONAL OUTCOMES AND COMPLICATIONS AFTER PARTIAL NEPHRECTOMY VERSUS PERCUTANEOUS RADIOFREQUENCY ABLATION IN SMALL SIZED (4CM OR LESS) BOSNIAK III OR IV CYSTIC RENAL LESIONS

You have accessJournal of UrologyKidney Cancer: Ablative Therapy1 Apr 2017MP100-07 COMPARISON OF ONCOLOGIC RESULTS, FUNCTIONAL OUTCOMES AND COMPLICATIONS AFTER PARTIAL NEPHRECTOMY VERSUS PERCUTANEOUS RADIOFREQUENCY ABLATION IN SMALL SIZED (4CM OR LESS) BOSNIAK III OR IV CYSTIC RENAL LESIONS Song Wan, Byung Kwan Park, Chan Kyo Kim, Young Hyo Choi, Hyun Woo Chung, Chung Un Lee, Jun Phil Na, Hwang Gyun Jeon, Byong Chang Jeong, Seong Il Seo, Seong Soo Jeon, Han Yong Choi, and Hyun Moo Lee Song WanSong Wan More articles by this author , Byung Kwan ParkByung Kwan Park More articles by this author , Chan Kyo KimChan Kyo Kim More articles by this author , Young Hyo ChoiYoung Hyo Choi More articles by this author , Hyun Woo ChungHyun Woo Chung More articles by this author , Chung Un LeeChung Un Lee More articles by this author , Jun Phil NaJun Phil Na More articles by this author , Hwang Gyun JeonHwang Gyun Jeon More articles by this author , Byong Chang JeongByong Chang Jeong More articles by this author , Seong Il SeoSeong Il Seo More articles by this author , Seong Soo JeonSeong Soo Jeon More articles by this author , Han Yong ChoiHan Yong Choi More articles by this author , and Hyun Moo LeeHyun Moo Lee More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.3114AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Partial nephrectomy (PN) has been increasingly used for the treatment of small renal mass. However, percutaneous radiofrequency ablation (RFA) has been accepted as a minimally invasive treatment option. In this study, we evaluated the oncologic results, functional outcomes and complications after PN or percutaneous RFA for the treatment of small sized (4cm or less) Bosniak III or IV cystic renal lesions. METHODS We retrospectively reviewed medical records of 135 patients who underwent PN (99) or RFA (36) for small sized (4cm or less) Bosniak III or IV cystic renal lesions between January 2009 and December 2014. After excluding patients with hereditary cystic disease or less than 12 months of follow-up, 128 (PN, 97; RFA, 31) patients remained for analysis. Pathologic characteristics, tumor violation during surgery, residual tumor, local recurrence and distant metastasis data were collected. Glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations and checked preoperatively, 1 month, 6 months, and 12 months postoperatively. All complications were graded by Clavien classification system. RESULTS The median size of Bosniak III or IV cystic renal lesions was 2.6cm. Renal cell carcinoma (RCC) accounted for 86.6% (84/97) of patients in PN group. In RFA group, histologic subtype was identified in 32.3% (10/31) of patients, but 90.0% (9/10) of patients revealed RCC. One case of tumor violation occurred in PN group and 2 cases of residual cancer were observed in RFA group. But there were no local recurrence or distance metastasis in both groups during the median follow-up of 34.0 months. Compared with PN group, patients in the RFA group showed a small decrease of percent change of CKD-EPI GFR at 1 month (-13.6% vs -6.8%, p=0.039). Perioperative complication rate in PN group was 29.9% and 22.6% in RFA group. According to Clavien classification system, Grade IIIa complications rate was 4.1% in PN group and 6.5% in RFA group. There were no grade IIIb and IV complications CONCLUSIONS The results of our study indicated that percutaneous RFA showed comparable oncologic results and complications and better early preservation of renal functions than PN. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1332 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Song Wan More articles by this author Byung Kwan Park More articles by this author Chan Kyo Kim More articles by this author Young Hyo Choi More articles by this author Hyun Woo Chung More articles by this author Chung Un Lee More articles by this author Jun Phil Na More articles by this author Hwang Gyun Jeon More articles by this author Byong Chang Jeong More articles by this author Seong Il Seo More articles by this author Seong Soo Jeon More articles by this author Han Yong Choi More articles by this author Hyun Moo Lee More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

CUA guideline on the management of cystic renal lesions.

CUA guideline on the management of cystic renal lesions.

Crizotinib Associated Renal Cysts [CARCs]: incidence and patterns of evolution

BackgroundNovel therapeutic agents recently introduced for the treatment of cancer have several unusual side effects. An increased incidence of renal cystic lesions, often with features concerning for malignancy or infection, has been reported in patients with anaplastic lymphoma kinase (ALK) - rearranged advanced non-small cell lung cancer (NSCLC) treated with Crizotinib. Many of these lesions undergo spontaneous resolution despite developing complex features on imaging. We assess the incidence and patterns of evolution of Crizotinib Associated Renal Cysts [CARCs] at our institute and provide histopathology correlation of their benign nature.MethodsA retrospective analysis of renal lesions in computerised tomography (CT) scans of 35 patients with advanced ALK-rearranged NSCLC who had been prescribed crizotinib at our institution was performed by three radiologists, who analysed the evolution of these lesions, particularly for pre-defined significant and complex changes.ResultsOf 26 patients eligible for this analysis, 4 (15%) had cysts at baseline that remained stable on crizotinib treatment while 11(42%) developed significant change in 28 renal cysts. Commonest pattern of cyst evolution was enlargement from baseline followed by spontaneous regression (17/28 lesions) while other patterns noted were stable lesions, regression from baseline and ongoing enlargement. The median maximum size reached was 23 mm (range 9 – 67 mm) after a median of 178 days (160 to 1342) on crizotinib. Complex change occurred in 12 cysts, in 7/26 (27%) patients and within 60 days of starting Crizotinib in 10 cysts. Imaging features were falsely concerning for malignancy or abscess in 4/26 patients.ConclusionMost CARCs resolve spontaneously, or have a benign evolution despite enlargement and other features concerning for malignancy or infection on imaging. This unusual manifestation of chemotherapy should be recognised, particularly by radiologists, so that inappropriate treatment decisions are avoided.

CEUS of Problematic Renal Masses: Comparison with CECT and CEMRI

Ultrasound (US) is often the first-line imaging modality in the evaluation of the renal masses. If the findings of a renal mass do not meet all of US criteria of a simple cyst, it should be characterized further. Usually characterization of indeterminate renal masses is well done with CT or MRI, but sometimes it is inconclusive on these imaging techniques. In thoses cases and in patients to whom radiation exposure or use of iodine or gadolinium contrast agents is undesirable, contrast-enhanced US (CEUS) may be a valuable alternative to evaluate those problematic renal masses. CEUS may replace CECT or CEMRI if the patient has marginal or poor renal function, hypersensitivity to iodine contrast agent, or fear of radiation exposure. CEUS has long history in medical US but drew attention only recently. With the first generation microbubble agents several studies showed added value of CEUS as compared to the conventional Doppler US. We reported that CEUS provided better visualization of tumor vascularity in indeterminate cystic renal lesions than other imaging modalities using a first-generation agtent. The most important limitation of the first generation agent was that it could not provide an enough duration of contrast enhancing effect. With introduction of the second generation microbubble agents with better stability and duration of contrast effect, CEUS examination became a practical alternative of CECT or CEMRI in evaluation of problematic renal masses. We do not think that CEUS will be used routinely in US examination of renal masses like contrast enhancement is routine in CT for renal masses. However, we are sure that CEUS will be a valuable imaging technique if it is used in well selected cases of problematic renal masses. In evaluating problematic renal masses, CEUS may reveal findings that were not seen or confirm findings equivocal at other imaging studies. Results of CEUS can be analyzed qualitatively as to the presence or absence of enhancement, vascular pattern and heterogeneity etc. Quantitative analysis can be done on peak intensity, time to peak, and rate of wash-in and wash-out, etc.

Malignancy rates and diagnostic performance of the Bosniak classification for the diagnosis of cystic renal lesions in computed tomography \u2013 a systematic review and meta-analysis

ObjectiveTo systematically review the literature on the Bosniak classification system in CT to determine its diagnostic performance to diagnose malignant cystic lesions and the prevalence of malignancy in Bosniak categories.MethodsA predefined database search was performed from 1 January 1986 to 18 January 2016. Two independent reviewers extracted data on malignancy rates in Bosniak categories and several covariates using predefined criteria. Study quality was assessed using QUADAS-2. Meta-analysis included data pooling, subgroup analyses, meta-regression and investigation of publication bias.ResultsA total of 35 studies, which included 2,578 lesions, were investigated. Data on observer experience, inter-observer variation and technical CT standards were insufficiently reported. The pooled rate of malignancy increased from Bosniak I (3.2 %, 95 % CI 0–6.8, I2 = 5 %) to Bosniak II (6 %, 95 % CI 2.7–9.3, I2 = 32 %), IIF (6.7 %, 95 % CI 5–8.4, I2 = 0 %), III (55.1 %, 95 % CI 45.7–64.5, I2 = 89 %) and IV (91 %, 95 % CI 87.7–94.2, I2 = 36). Several study design-related influences on malignancy rates and subsequent diagnostic performance indices were identified.ConclusionThe Bosniak classification is an accurate tool with which to stratify the risk of malignancy in renal cystic lesions.Key points• The Bosniak classification can accurately rule out malignancy.• Specificity remains moderate at 74 % (95 % CI 64–82).• Follow-up examinations should be considered in Bosniak IIF and Bosniak II cysts.• Data on the influence of reader experience and inter-reader variability are insufficient.• Technical CT standards and publication year did not influence diagnostic performance.

Distinguishing malignant and benign renal masses with composite models and nomograms: A systematic review and meta-analysis of clinically localized renal masses suspicious for malignancy.

Solid renal masses and cystic lesions with solid components are suspicious for renal cell carcinoma. Without an effective screening test, composite models and nomograms rely on patient and tumor characteristics to stratify the risk of benign disease versus malignant disease. To guide decisions about the use of renal mass sampling or excision, a systematic review and meta-analysis of the ability of composite models to predict the likelihood of malignancy on the basis of preoperative clinical variables was performed. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from January 1, 1997, through May 1, 2015, according to the Preferred Reporting Items for Systematic Review and Meta-Analyses statement. Composite models necessarily included imaging results and at least 1 element from the following to be compared with surgical pathology: demographic characteristics, clinical characteristics, and blood or urine tests. Two independent reviewers screened citations and extracted data. Quality Assessment Tool for Diagnostic Accuracy Studies 2 was used to assess the risk of bias. The strength of evidence was graded with the scheme recommended by Methods Guide for Effectiveness and Comparative Effectiveness Reviews. Twenty studies (12,149 patients) were included in this review. The only significant predictors of malignancy in the composite models were tumor size (effect size, 1.33-fold increased risk per centimeter; 95% confidence interval [CI], 1.22-1.43) and male sex (effect size, 2.71; 95% CI, 2.39-3.02). The results were inconclusive or not significant for tumor characteristics, age, body mass index, and incidental presentation. In conclusion, composite models currently have a limited ability to distinguish malignant renal masses from benign renal masses, with increased tumor size and male sex associated with malignancy. Cancer 2016;122:3267-3276. © 2016 American Cancer Society.

Combined deletion of Vhl, Trp53 and Kif3a causes cystic and neoplastic renal lesions.

The von Hippel-Lindau (VHL) tumour suppressor gene is bi-allelically inactivated in the majority of cases of clear cell renal cell carcinoma (ccRCC); however, Vhl knockout mouse models do not recapitulate human ccRCC, implying that additional mutations are required for tumour formation. Mutational inactivation of VHL sensitises renal epithelial cells to lose the primary cilium in response to other mutations or extracellular stimuli. Loss of cilia is believed to represent a second hit in VHL mutant cells that causes the development of cystic lesions that, in some cases, can progress to ccRCC. Supporting this idea, genetic ablation of the primary cilium by deletion of the kinesin family member 3A (Kif3a) gene cooperates with loss of Vhl to accelerate cyst formation in mouse kidneys. Additionally, aged Vhl/Trp53 double-mutant mice develop renal cysts and tumours at a relatively low incidence, suggesting that there is a genetic cooperation between VHL and TP53 mutation in the development of ccRCC. Here we generated renal epithelium-specific Kif3a/Trp53 and Vhl/Kif3a/Trp53 mutant mice to investigate whether primary cilium deletion would accelerate the development of cystic precursor lesions or cause their progression to ccRCC. Longitudinal microcomputed tomography (μCT) imaging and histopathological analyses revealed an increased rate of cyst formation, increased proportion of cysts with proliferating cells, higher frequency of atypical cysts as well as the development of neoplasms in Vhl/Kif3a/Trp53 mutant kidneys compared to Kif3a/Trp53 or Vhl/Kif3a mutant kidneys. These findings demonstrate that primary cilium loss, in addition to Vhl and Trp53 losses, promotes the transition towards malignancy and provide further evidence that the primary cilium functions as a tumour suppressor organelle in the kidney. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Value of Contrast-Enhanced Ultrasonography and Contrast-Enhanced CT in the Diagnosis of Malignant Renal Cystic Lesions: A Meta-Analysis.

We compared the efficacy of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) for the diagnosis of renal cystic lesions via a meta-analysis to determine the value of CEUS in the prediction of the malignant potential of complex renal cysts. Eleven studies were evaluated: 4 control studies related to CEUS and CECT, 3 studies related to CEUS and 4 studies related to CECT. According to the random effects model, the pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for CEUS/CECT were 0.95/0.90, 0.79/0.85, 4.39/5.00, and 0.10/0.15, respectively. The areas under the summary receiver operating characteristic (AUCs-SROC) curves for the two methods were 94.24% and 93.39%, and the estimated Q values were 0.8805 and 0.8698, respectively. Comparing the Q index values of CEUS and CECT revealed no significant difference between the two methods (P>0.05). When compared with conventional CECT, CEUS is also useful for diagnosing renal cystic lesions in the clinic.

Contrast-Enhanced Ultrasound (CEUS) of the Kidneys by Using the Bosniak Classification.

Ultrasound is the most used interdisciplinary non-ionizing imaging technique in clinical routine. Therefore, ultrasound has a special value in the diagnosis and monitoring of cystic renal lesions, which can be classified as non-complicated or complicated and by means of occurrence as solitary or multifocal lesions. The Bosniak classification (I-IV) classifies renal cysts in 5 different categories with the help of ultrasound and computed tomography image criteria and is used for decisions of further clinical treatment. Additionally to normal native B-mode sonography, several new methods are in clinical use to improve diagnostic accuracy of unclear cases. Contrast enhanced ultrasound and MRI/CT are able to find and characterize difficult pathologies. This review explains the most important pathologies of cystic lesions of the kidney and stresses the different imaging methods of native B-mode sonography and the new techniques of contrast enhanced ultrasound.

Management of incidental renal masses: Time to consider contrast-enhanced ultrasonography.

Proliferation of imaging studies for different clinical purposes and continuous improvement of imaging technology have led to an increasing number of incidental findings of renal masses. It is estimated that over 50% of patients older than 50 years have at least one renal mass. The majority of incidental renal masses are simple cysts that can be easily diagnosed by conventional ultrasonography. However, some incidental renal masses are not simple cysts, and differentiation between benign and malignant entities requires further imaging modalities. In the past, multiphase contrast-enhanced computed tomography and magnetic resonance imaging were considered the primary imaging modalities used to characterize and stage complex cystic and solid renal lesions. Currently, contrast-enhanced ultrasonography represents a novel alternative to contrast-enhanced computed tomography and magnetic resonance imaging. Contrast-enhanced ultrasonography employs microbubble contrast agents that allow the study of different enhancement phases of the kidney without risk of nephrotoxicity and radiation exposure. The diagnostic accuracy of contrast-enhanced ultrasonography in the characterization of complex renal cysts is comparable to that of computed tomography and magnetic resonance imaging, and several studies have demonstrated its reliability also in identifying solid lesions such as pseudotumors, typical angiomyolipomas, and clear cell renal carcinomas. Considering the high incidence of incidental renal masses and the need for rapid and reliable diagnosis, contrast-enhanced ultrasonography could be proposed as the first step in the diagnostic work-up of renal masses because of its safety and cost effectiveness. In this paper, we propose a diagnostic algorithm for the characterization of cystic and solid renal masses.

Usefulness of diffusion-weighted magnetic resonance imaging for the characterization of benign and malignant renal lesions

PurposeOur aim was to evaluate the diagnostic potential of diffusion-weighted magnetic resonance imaging (DW-MRI) and quantitative assessment of apparent diffusion coefficient (ADC) value for the characterization of renal lesions and differentiation into benign and malignant. Patients and methodsA total of 87 consecutive patients with 107 renal lesions were enrolled in this prospective study. MRI examinations including DWI with b factors of 0, 600 and 800s/mm2 were performed at 1.5T MRI unit. The mean ADC values of normal renal parenchyma, solid and cystic lesions were calculated. ResultsThere was statistical significance difference between ADC value of normal renal parenchyma with that of benign (n=60, 56%) and malignant (n=47, 44%) renal lesions (P value<0.0001). ADC values differed significantly between solid (n=74, 69.2%) and cystic lesions (n=33, 30.8%) (P value<0.0001). There was significant difference between ADC values of all benign (n=60, 56%) and malignant renal lesions (n=47, 44%) (P value<0.0001) but not between benign solid (n=27, 36.5%) and malignant solid renal lesions (n=47, 63.5%) (P value=0.784). ConclusionThere is overlap between the ADC values of benign and malignant lesions. The use of ADC value alone may lead to inaccurate assessment of renal lesions. Thus, DW-MRI should be interpreted in conjunction with conventional MRI sequences to allow for better characterization of renal lesions.

Association between renal cystic lesions and bilateral Wilms' tumours.

Evaluate a potential association between Wilms' tumour (WT) and renal cystic lesions. Digital records and imaging files of consecutive patients diagnosed with WT between 2004 and 2014 were retrospectively reviewed under an Institutional Review Board waiver of informed consent. The locations of renal cysts seen on US, CT, and/or MRI were recorded and compared with the locations of newly developed WT. A total of 48 patients (mean age 3years 9months) presented with newly diagnosed WT in the study period. Mean follow-up was 4.5 (range 1-10) years. WT was unilateral in 40 children, bilateral in 8. Renal cysts were identified in only one of the forty patients (2.5%) with unilateral disease - in the contralateral kidney. In contrast, renal cysts were found in seven of eight patients with bilateral WT (87.5%), in two of whom, new tumours developed in the same location where cysts had been seen on previous imaging studies. Renal cystic lesions in patients with Wilms' tumour should be regarded as potential tumour precursors, and followed with frequent imaging. • Cortical renal cystic lesions have a high association with bilateral Wilms' tumour. • In children with Wilms' tumour renal cysts are possible tumour precursors. • MRI appears to be the best modality in depicting the cortical cysts.

Role of US Contrast Agents in the Assessment of Indeterminate Solid and Cystic Lesions in Native and Transplant Kidneys.

Ultrasonography (US) is often the initial imaging modality employed in the evaluation of renal diseases. Despite improvements in B-mode and Doppler imaging, US still faces limitations in the assessment of focal renal masses and complex cysts as well as the microcirculation. The applications of contrast-enhanced US (CEUS) in the kidneys have dramatically increased to overcome these shortcomings with guidelines underlining their importance. This article describes microbubble contrast agents and their role in renal imaging. Microbubble contrast agents consist of a low solubility complex gas surrounded by a phospholipid shell. Microbubbles are extremely safe and well-tolerated pure intravascular agents that can be used in renal failure and obstruction, where computed tomographic (CT) and magnetic resonance (MR) imaging contrast agents may have deleterious effects. Their intravascular distribution allows for quantitative perfusion analysis of the microcirculation, diagnosis of vascular problems, and qualitative assessment of tumor vascularity and enhancement patterns. Low acoustic power real-time prolonged imaging can be performed without exposure to ionizing radiation and at lower cost than CT or MR imaging. CEUS can accurately distinguish pseudotumors from true tumors. CEUS has been shown to be more accurate than unenhanced US and rivals contrast material-enhanced CT in the diagnosis of malignancy in complex cystic renal lesions and can upstage the Bosniak category. CEUS can demonstrate specific enhancement patterns allowing the differentiation of benign and malignant solid tumors as well as focal inflammatory lesions. In conclusion, CEUS is useful in the characterization of indeterminate renal masses and cysts.

Tubulocystic renal cell carcinoma: a new radiological entity.

Tubulocystic renal cell carcinoma (TC-RCC) is a recently identified renal malignancy. While approximately 100 cases of TC-RCC have been reported in the pathology literature, imaging features have not yet been clearly described. The purpose of this review is to describe the main radiologic features of this rare sub-type of RCC on ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), based jointly on the literature and findings from a multi-institutional retrospective HIPAA-compliant review of pathology and imaging databases. Using a combination of sonographic and CT/MRI features, diagnosis of TC-RCC appeared to be strongly suggested in many cases. • Tubulocystic renal cell carcinoma is a new entity with typical imaging features • Diagnosis of tubulocystic renal cell carcinoma can be suggested preoperatively by imaging • Cystic renal lesions with high echogenicity may correspond to tubulocystic carcinoma.

Approach to Very Small (< 1.5 cm) Cystic Renal Lesions: Ignore, Observe, or Treat?

This article will review the current available literature on the prevalence, behavior, and pathology of very small (< 1.5 cm) cystic renal lesions. A summary of the recommended approach to these very small lesions is provided. Limited data exist to guide the management of very small cystic renal lesions. Because most data favor benign or indolent behavior, vigorous workup of the very small cystic renal lesion seems unnecessary.

Potential Role of Tc-99m DTPA Diuretic Renal Scan in the Diagnosis of Calyceal Diverticulum in Children.

The aim of the study was to assess the usefulness of Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) diuretic scan to diagnose calyceal diverticulum (CD).From January 2000 to June 2014, children with evidence of renal cystic lesions of undetermined diagnosis on ultrasound were enrolled. Computed tomography urography (CTU) and Tc-99m DTPA diuretic scan were performed to characterize the precise anatomy. The diagnosis of CD depended on visualization of a renal cystic lesion with filling of contrast material or radiotracer from the collecting system on CTU or diuretic renal scan. Children who had positive findings of CD on 1 or both imaging studies were selected and analyzed.Both CTU and Tc-99m DTPA diuretic renal scan were performed in 39 children. A total of 9 (23.1 %) children with CD were diagnosed. All 9 children had positive diagnosis of CD on diuretic renal scan. Only 6 (66.7%) children could be diagnosed by CTU, and CD was missed by CTU in 3 subjects. The differential renal functions in patients with CD were 46% to 55%. The time of radiotracer appearance in the CD ranged from the 8th to the 24th minute. Seven patients had persistent accumulation of radiotracer in their CD at the end of the study.Tc-99m DTPA diuretic renal scan seems to be more sensitive than CTU in diagnosing CD. The possible reasons of higher sensitivity are discussed. Additional advantages that Tc-99m DTPA diuretic renal scan provides include the following: continuous monitoring, less radiation doses, and information on renal function, making it an attractive alternative to CTU for diagnosis of CD.

Outcomes and complications related to the management of Bosniak cystic renal lesions.

The objective of our study was to evaluate outcomes and complications related to the management of Bosniak category IIF, III, and IV renal cysts. For this multiinstitutional retrospective study, a Web-based Research Electronic Data Capture (REDCap) data registry was used to record data of 286 adult patients with 312 prospectively classified Bosniak IIF, III, and IV renal cysts diagnosed between January 2000 and October 2011. Included patients were managed by surgery (n = 86), percutaneous ablation (n = 19), or imaging surveillance of 1 year or more (n = 181). The median number of years of clinical surveillance was 2.4 years (range, 0-11.7 years), 2.6 years (range, 0.4-11.4 years), and 3.2 years (range, 1.1-11.6 years) for patients managed by surgery, ablation, and imaging surveillance, respectively. Pathologic and survival outcomes and complications related to management were evaluated. The malignancy rate at surgical pathology was 38% (3/8) for Bosniak IIF, 40% (29/72) for Bosniak III, and 90% (18/20) for Bosniak IV renal cysts. There were no metastases or deaths (0/144) directly related to Bosniak IIF renal cysts. There were no deaths (0/113) directly related to Bosniak III renal cysts, although one patient (1/113) developed local progression and lung metastases after thermal ablation. One patient with a Bosniak IV renal cyst (1/29) presented with and died of metastatic disease. Moderate to severe complications occurred in 19% (16/86), 5% (1/19), and 0% (0/181) of patients managed by surgery, ablation, and imaging surveillance, respectively (p < 0.0001). Severe complications occurred in 7% (6/86) of surgical patients and included multiorgan failure (n = 2), acute myocardial infarction (n = 1), acute ischemic stroke (n = 1), conversion to hemodialysis-dependent chronic kidney disease (n = 1), and postoperative severe hemorrhage (n = 1). There were no deaths from Bosniak IIF or III renal cysts regardless of management approach. Moderate to severe complications are frequent in patients managed by surgery.