A New Nephrometry Score for Predicting Positive Surgical Margin After Laparoscopic Partial Nephrectomy

PURPOSE

To introduce the KESKIN ratio as a novel predictor of positive surgical margin (PSM) after laparoscopic partial nephrectomy (PN) and to evaluate other clinical characteristics and nephrometry scores (including RENAL, PADUA, and C-index) for predicting PSM.

METHODS

We retrospectively analyzed 95 patients who underwent laparoscopic PN between June 2020 and April 2023. The KESKIN ratio was defined for all patients. The KESKIN ratio, tumor and patient-related paramaters, and nephrometry scores were analyzed to predict PSM.

RESULTS

Positive surgical margin was found in 12 of 95 patients (12.6%). There was no statistical difference between the PSM and negative surgical margin (NSM) groups in RENAL, PADUA, and C-index scores. Only the KESKIN ratio was found to be a statistically significant predictor of PSM in both univariate and multivariate regression analysis (p = 0.007 and p = 0.043, respectively). Mean endophytic diameter and endophytic percentage were found to be statistically significant predictors of PSM in only univariate analysis (p = 0.005 and p = 0.01, respectively). The value of 0.5 was determined as the cut-off value for the KESKIN ratio. Values higher than 0.5 indicate an increase in PSM.

CONCLUSIONS

The KESKIN ratio is a novel, easily measurable, and calculable image-based parameter that can be used to predict PSM after laparascopic PN. If externally validated in a larger patient population, the KESKIN ratio may be used in future versions of the current nephrometry scoring systems for predicting the PSM.

Perioperative and Survival Outcomes of Patients Treated With Robot-Assisted Partial Nephrectomy and Percutaneous Microwave Ablation for Small Renal Masses: A Single Center Experience

BACKGROUND

Robot assisted partial nephrectomy (RAPN) and microwave ablation (MWA) are 2 of the most advanced techniques for the management of localized small renal masses.

PURPOSE

To compare the perioperative, functional and oncological results of RAPN and MWA.

MATERIALS AND METHODS

Data from 171 consecutive patients undergoing either RAPN or MWA for a localized small renal mass at a single academic center was retrospectively collected. Baseline features included patients' demographics and masses' characteristics. Procedures were compared in terms of perioperative outcomes and renal function variation Progression of a persistent lesion or local recurrence after a complete treatment defined local tumor progression. Descriptive statistics and survival analysis tested the association between predictors and local tumor progression.

RESULTS

Of all, 109 and 62 patients underwent RAPN and MWA. Patients in the MWA group were older (P = .002) had higher Charlson Comorbidity Index (CCI) (P < .001) and higher frequency of preoperative chronic kidney disease (P < .001). MWA led to a shorter postoperative hospitalization time (P < .001) and lower incidence of medical complications (6.5% vs. 22.9%, P = .02) than RAPN. GFR decline was similar between groups both at discharge (P = .39) and at the time of last follow up (P = 1.00). A lower rate of secondary interventions (11.7% vs. 2.8%, P = .037) and a better disease-free survival (83.2% vs. 96.5%, P = .027) were reported after RAPN. Conversely, cancer specific and overall survival were comparable (P > .05). At univariate regression analysis, MWA was associated with local tumor progression (HR 3.46, P = .040).

CONCLUSION

MWA displayed a lower perioperative impact, while functional outcomes were similar after each intervention. RAPN resulted superior in terms of tumor eradication, but no difference was noted regarding cancer specific survival. Thus, MWA represents a valid alternative in frail patients, though less radical than RAPN.

Ossifying renal tumor of infancy: A case report

Ossifying Renal Tumor of Infancy (ORTI) represents an extremely rare and benign renal neoplasm, with limited cases published in the literature. Predominantly characterized by painless and intermittent gross hematuria, the diagnostic evaluation is effectively facilitated through ultrasound, computed tomography, and magnetic resonance imaging. Despite progress, its etiology has not yet been elucidated. We report an additional case with an unusual clinical presentation.

Actual encounters of the kidney kind: Exploring 48 cases of renal collision tumors through the lens of literature

Multiple tumors of different lineages merging into a single mass, termed collision tumors, are considered a rare phenomenon in the kidney. Tumor components, or partners, may be malignant (including metastatic disease), borderline, or benign. We report the largest cohort to date of 48 cases. The cases were identified from the archives of three institutions in the last 16 years, including 43 (90%) with 2 tumor partners (dyad) and 5 (10%) with 3 partners (triad), totaling 101 individual neoplasms. The majority of cases involved immunohistochemical workup, and 5 underwent FISH or molecular studies. Forty (83%) cases featured a malignant entity, including all triads. Twenty dyads and two triads were composed entirely of malignant tumors. The most common malignant partner was clear cell renal cell carcinoma (RCC) (N = 19) followed by papillary RCC (N = 17). Nine (19%) cases featured borderline entities, including 5 multilocular cystic neoplasms of low malignant potential and 6 clear cell papillary renal cell tumors. Twenty one (44%) cases contained a benign partner, including 6 benign dyads. Papillary adenoma (N = 13) and oncocytoma (N = 8) were most common. Epithelial tumors were present in all 48 cases, and non-epithelial neoplasms in 9 cases (19%). Our cohort includes many novel combinations and collision partners with rare entities such as SDH-deficient RCC, TFE3-rearranged RCC, eosinophilic solid and cystic RCC, and acquired cystic disease associated RCC. A comprehensive literature review and analysis of collision tumor phenomenon in kidney placed these cases in context suggesting that collision tumors of the kidney are more common than previously recognized.

Imaging-based deep learning in kidney diseases: recent progress and future prospects

Kidney diseases result from various causes, which can generally be divided into neoplastic and non-neoplastic diseases. Deep learning based on medical imaging is an established methodology for further data mining and an evolving field of expertise, which provides the possibility for precise management of kidney diseases. Recently, imaging-based deep learning has been widely applied to many clinical scenarios of kidney diseases including organ segmentation, lesion detection, differential diagnosis, surgical planning, and prognosis prediction, which can provide support for disease diagnosis and management. In this review, we will introduce the basic methodology of imaging-based deep learning and its recent clinical applications in neoplastic and non-neoplastic kidney diseases. Additionally, we further discuss its current challenges and future prospects and conclude that achieving data balance, addressing heterogeneity, and managing data size remain challenges for imaging-based deep learning. Meanwhile, the interpretability of algorithms, ethical risks, and barriers of bias assessment are also issues that require consideration in future development. We hope to provide urologists, nephrologists, and radiologists with clear ideas about imaging-based deep learning and reveal its great potential in clinical practice.Critical relevance statement The wide clinical applications of imaging-based deep learning in kidney diseases can help doctors to diagnose, treat, and manage patients with neoplastic or non-neoplastic renal diseases.Key points• Imaging-based deep learning is widely applied to neoplastic and non-neoplastic renal diseases.• Imaging-based deep learning improves the accuracy of the delineation, diagnosis, and evaluation of kidney diseases.• The small dataset, various lesion sizes, and so on are still challenges for deep learning.

A rare case report of recurrent primary intra-abdominal synovial sarcoma: An unusual manifestation

Synovial sarcomas are a rare and aggressive subtype of soft tissue sarcomas that typically affects young adults and involves the extremities. Synovial sarcoma of the kidney is a rare and aggressive tumor with a poor prognosis, accounting for only 1% of all renal tumors. The imaging features of this tumor often overlap with those of other renal tumors, and a definitive diagnosis can only be made through immunohistochemical analysis. In this case report, we present the case of a 55-year-old female with left flank pain, who was diagnosed with primary renal synovial sarcoma following a left-sided radical nephrectomy. Despite initial successful surgical intervention, restaging scans showed local recurrence and metastatic disease, which was subsequently managed with 6 cycles of chemotherapy followed by radiation therapy with palliative intent. This case underscores the importance of early detection and aggressive management of rare renal tumors to improve patient outcomes.

Amide proton transfer-weighted MRI for renal tumors: Comparison with diffusion-weighted imaging

OBJECTIVE

To investigate the potential of amide proton transfer-weighted (APTw) MRI in identifying benign and malignant renal tumors and to evaluate whether APTw MRI can add diagnostic value to diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Participants with renal tumor underwent preoperative multiparametric MRI, including APTw MRI and DWI. The APTw and apparent diffusion coefficient (ADC) of malignant tumors and benign tumors were calculated independently by two radiologists and compared. The value of the mean APTw and the mean ADC for differentiating malignant and benign tumors was evaluated by receiver operating characteristic analysis.

RESULTS

In total, 65 participants (mean age, 59 years ±14; 41 men) were evaluated: 54 with malignant and 11 with benign renal tumors. Malignant renal tumors showed higher mean APTw values [2.03% (1.63) vs 1.00% (1.60); P < 0.01] and lower mean ADC values (1.22 × 10-3 mm2/s ± 0.37 vs 1.51 × 10-3 mm2/s ± 0.37; P < 0.05) than benign renal tumors. The area under the receiver operating characteristic curve (AUC) of APTw, ADC and the combination of them for the identification of benign and malignant renal tumors was 0.78(95% CI: 0.66, 0.87; P < 0.001),0.70(95% CI: 0.54, 0.86; P < 0.05) and 0.79 (95% CI: 0.67, 0.88; P < 0.001). The optimal cutoff value for mean APTw was 2.14% (sensitivity, 74%; specificity, 73%). There was no difference between these three parameters for differentiating malignant from benign renal tumors (P > 0.05).

CONCLUSION

The APTw MRI has the potential use as an imaging biomarker for renal malignant and benign tumors.

Primary follicular dendritic cell sarcoma of the kidney - a case report of a rare tumor with emphasis on diagnostic pitfalls

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare low-grade tumor of the lymph nodes, but roughly one-third of the cases emerge from extranodal sites, posing diagnostic challenges.

CASE PRESENTATION

In this report, we present the case of a 59-year-old lady who complained of renal colic. During investigation, a kidney tumor was discovered. A radical nephrectomy was performed, and histological examination identified the tumor as a sarcomatoid renal cell carcinoma. The case was then referred to a genitourinary pathologist for further evaluation. The tumor cells exhibited positive staining for CD21, CD23, somatostatin receptor 2 A, and MDM2 expression. Additionally, MDM2 gene amplification was confirmed by the FISH study. Ultimately, the tumor was diagnosed as a primary renal FDCS. The patient was placed under active oncological surveillance and did not receive any further therapy. Remarkably, after 91 months of follow-up, she remains tumor-free.

CONCLUSION

This case represents a well-documented primary renal FDCS. Our aim in presenting this extremely rare tumor is to enhance awareness and highlight the importance of considering FDCS in the differential diagnosis.

A case of renomedullary interstitial cell tumor: Radiologic-pathologic correlation

Renomedullary interstitial cell tumor (RMICT), referred to as a medullary fibroma, is almost always asymptomatic and incidentally identified either at autopsy or upon resection of the kidney for other reasons. Although a few cases of RMICTs that are large in size and clinically symptomatic have been reported, there are few reports of RMICTs contrasting imaging findings with pathological findings. In this report, we describe a relatively large RMICT case of 3 cm in size, focusing on the radiologic-pathologic correlation.

Dataset on renal tumor diameter assessment by multiple observers in normal-dose and low-dose CT

Computed tomography-based active surveillance is increasingly used to manage small renal tumors, regardless of patient age. However, there is an unmet need for decreasing radiation exposure while maintaining the necessary accuracy and reproducibility in radiographic measurements, allowing for detecting even minor changes in renal mass size. In this article, we present supplementary data from a multiobserver investigation. We explored the accuracy and reproducibility of low-dose CT (75% dose reduction) compared to normal-dose CT in assessing maximum axial renal tumor diameter. Open-access CT datasets from the 2019 Kidney and Kidney Tumor Segmentation Challenge were used. A web-based platform for assessing observer performance was used by six radiologist observers to obtain and provide data on tumor diameters and accompanying viewing settings, in addition to key images of each measurement and an interactive module for exploring diameter measurements. These data can serve as a baseline and inform future studies investigating and validating lower-dose CT protocols for active surveillance of small renal masses.

What is the benefit of gadolinium-chelate injection for the diagnosis of local recurrence of clear cell renal cell carcinoma after percutaneous thermal ablation with MRI?

PURPOSE

The purpose of this study was to compare the diagnostic capabilities of contrast-enhanced (CE)-MRI to those of non-CE-MRI to diagnose local recurrence of clear cell renal cell carcinoma (ccRCC) after percutaneous thermal ablation (TA).

MATERIALS AND METHODS

This institutional, review board-approved, case-control, single-center retrospective study included all consecutive adult patients with at least two post-TA MRIs showing local recurrence of ccRCC after TA validated by multidisciplinary board. 'Control' patients without recurrence were randomly-selected with a case:control ratio of 2/3. Four senior radiologists reviewed in a double-blinded fashion non-CE sequences of last two consecutive MRI examinations (non-CE-MRIs), assessed the presence of recurrence of ccRCC, then reviewed the CE sequences (CE-MRI) and determined again the presence of a recurrence. Area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy were compared for each reader for non-CE-MRI and CE-MRI.

RESULTS

Fifty-one patients (41 men; mean age, 77.5 years) who underwent percutaneous TA for ccRCC were included. There were a total of 21 recurrences and 35 scars. Whoever the reader, AUROC was not significantly different (mean, 0.86 with-CE-MRI vs. 0.81 with non-CE-MRI; P values ranging between 0.08 and 0.98), neither sensitivity (mean, 76.2% with CE-MRI vs. 71.4% with non-CE-MRI; P values ranging between 0.06 and >0.99), nor accuracy (85.8% with CE-MRI vs. 80.8% with non-CE-MRI; P values ranging between 0.07 and >0.99). Change in specificity depended on the reader with a significant increase for one reader (+20%; P = 0.02) and a significant decrease for another reader (-17.2%; P = 0.03).

CONCLUSION

Non-CE MRI has good diagnostic performance for the follow-up of patients with ccRCC treated using percutaneous TA, questioning the systematic use of GBCA injection.

Percutaneous ablation of renal tumors: Long-term outcomes

OBJECTIVE

To evaluate the long-term outcomes of renal tumor ablation, analyzing efficacy, long-term survival, and factors associated with complications and therapeutic success.

MATERIAL AND METHODS

We retrospectively reviewed 305 ablations (generally done with expandable electrodes) of 273 renal tumors between May 2005 and April 2019. We analyzed survival, primary and secondary efficacy, and complications according to various patient factors and tumor characteristics.

RESULTS

Mean blood creatinine was 1.14 mg/dL before treatment and 1.30 mg/dL after treatment (p < 0.0001). Complications were observed in 13.25% of the ablations, including major complications in in 4.97%. Complications were associated with age (p = 0.013) and tumor diameter (p < 0.0001). Primary efficacy was 96.28%. Incomplete ablation was more common in lesions measuring > 4 cm in diameter (p = 0.002). Secondary efficacy was 95.28%. The only factor associated with the risk of recurrence was the size of the tumor (p = 0.02). Overall survival was 95.26% at 1 year, 77.01% at 5 years, and 51.78% at 10 years, with no differences between patients with malignant and benign lesions. Mortality was higher in patients with creatinine >1 (p = 0.05) or ASA > 2 (p = 0.0001).

CONCLUSIONS

Percutaneous ablation is extremely efficacious for renal tumors; it improves the prognosis of renal carcinoma to the point where it does not differ from that of benign lesions. Complications are rare. Like survival, complications are associated with age and overall health status.

Critical elements of radical nephroureterectomy for pediatric unilateral renal tumor

Children with renal masses require surgical management to provide accurate surgical staging and skilled resection of the tumor. This document includes evidence-based recommendations for pediatric surgeons regarding the resection, staging, and proper nodal basin evaluation.

Utilizing RENAL nephrometry in pediatric patients undergoing nephron-sparing surgery for renal tumors: A single-institutional cohort

INTRODUCTION

RENAL Nephrometry is a complexity score validated in adults with renal tumors and describes the likelihood of complication after partial nephrectomy (PN). Utilization in pediatrics has been limited. Thus, our goal is to quantify inter-rater agreement as well as determine how scores correlate with outcomes. We hypothesize that the RENAL Nephrometry Score is reproducible in children with renal tumors and is related to perioperative and post-operative complications.

METHODS

All pediatric patients who underwent PN for a renal mass from 2006 to 2019 were identified. Patient data, operative details, and outcomes were aggregated. Pre-operative CT/MR imaging was anonymized and scored by 2 pediatric radiologists and 2 pediatric urologists using RENAL Nephrometry metrics. Statistical analysis utilized Fleiss' kappa and the intraclass correlation coefficient (ICC). Comparative analyses were performed based on Nephrometry Score <9 and ≥ 9.

RESULTS

28 patients undergoing 33 PN were identified. Median age at surgery was 3.2 years (IQR 1.8-4.0). There is moderate-good agreement across scorers on the domains of RENAL Nephrometry Score, with the lowest agreement noted for anterior vs posterior tumors. Comparing patients with scores <9 and ≥ 9, there was increased operative time (357 vs 267 min, p = 0.003) and LOS for those with a higher score, but no difference in the incidence of 30-day complications.

CONCLUSION

RENAL Nephrometry Score is an easily reproducible complexity score for renal tumors in pediatric patients. Higher scores are associated with increased length of stay and estimated blood loss but not complications. Reporting of nephrometry scores in future publications on pediatric renal tumors should become standard in the literature.

A juxtaglomerular cell tumor revealed by a hemorrhagic stroke. A case report

With about 110 cases reported in literature, juxtaglomerular cell tumors are rare. We report a 25 years old patient who was admitted in neurology for a hemorrhagic stroke secondary to a cerebral aneurysm rupture due to high blood pressure. Etiological investigations showed a solid mass of the left kidney. A radical nephrectomy was realized and pathological examination and immunohistochemical profile concluded to juxtaglomerular cell tumor. The originality of this observation is based on the mode of presentation of a rare renal tumor by a malignant high blood pressure.

Mixed epithelial and stromal tumor of the kidney with long-term imaging follow-up

Mixed epithelial and stromal tumor (MEST) of the kidney is a rare benign tumor with malignant potential, and is characterized by epithelial and stromal proliferation with a variety of cellularity and growth pattern. MEST of the kidney is often depicted as a well-defined, solid mass with a cystic component. However, due to the rarity of the disease, there are no reports of its progression in serial imaging examinations. This report presents the case of a 68-year-old woman with MEST who was followed for 13 years by computed tomography (CT). To the best of our knowledge, this is the first report of image findings of MEST of the kidney over a follow-up period longer than 10 years.

Wilms Tumor

Wilms tumor (WT), or nephroblastoma, is the most common primary malignant renal tumor of childhood. It is an embryonal tumor that develops from remnants of immature kidney. There are approximately 500 new WT cases diagnosed in the United States every year. Advances in multimodal therapy including surgery, chemotherapy, and radiation therapy given according to risk stratification have allowed most patients to achieve survival rates in excess of 90%.

Diagnostic value of pseudocapsule ring hyperenhancement in contrast-enhanced ultrasound in renal focal lesions

OBJECT

To investigate the diagnostic value of pseudocapsule ring hyperenhancement in contrast-enhanced ultrasound (CEUS) of focal renal lesions.

METHOD

Ninety eligible patients admitted were selected as the study subjects. The incidence rate of annular hyperenhancement in different benign and malignant focal lesions during angiography and the shape of annular enhancement were counted. The correlation between the occurrence of benign and malignant renal tumors and annular hyperenhancement and unenhanced areas was also analyzed.

RESULTS

Capsule enhancement was observed in 56 cases, including 50 cases of malignant tumors (89.3%, 50/56) and 6 cases of benign tumors (10.7%, 6/56). Pearson correlation analysis showed that renal malignancy was positively associated with the occurrence of pseudocapsule ring hyperenhancement (γ = 0.489, P < 0.001). Benign and malignant renal tumors were positively correlated with the occurrence of non-enhancing areas (γ = 0.215, P = 0.042). The thickness and peak intensity of pseudocapsule ring enhancement in renal malignant tumors were significantly higher than those in benign tumors (all P < 0.001), while the time to peak was significantly lower than that in benign tumors (P < 0.001). The results of receiver operating characteristic (ROC) curve showed that the ring enhancement thickness, time to peak, and area under ROC curve of peak intensity of tumor reached more than 0.9.

CONCLUSION

In CEUS, the pseudocapsule of focal renal lesions is a characteristic feature of renal malignant tumors, which can be used as a differential basis for benign and malignant tumors to improve the accuracy of benign and malignant renal tumors.

Efficacy and safety of MWA versus RFA and CA for renal tumors: A systematic review and meta-analysis of comparison studies

PURPOSE

Thermal ablation procedures represent an alternative treatment option for patients with T1a renal tumors. Radiofrequency ablation (RFA) and cryoablation (CA) are the most used and studied techniques, while microwave ablation (MWA) has progressively emerged in recent years. Our aim was to assess the effectiveness and safety of MWA in comparison to RFA and CA for the treatment of primary renal tumors.

METHOD

Pubmed, CENTRAL, Web of Science and Scopus were searched until March 2023 to identify studies aimed at comparing the efficacy and safety of MWA with those of RFA and CA for the treatment of patients with primary renal tumors. We compared MWA and RFA/CA primary technique efficacy, local recurrences, overall and cancer-specific survival, major and overall complications, and eGFR changes. Moreover, subgroup analyses were conducted (MWA vs RFA; MWA vs CA; MWA vs RFA/CA in T1a renal tumors).

RESULTS

Ten retrospective studies with 2258 thermal ablations were included (508 MWA and 1750 RFA /CA). MWA had fewer local recurrences (OR = 0.31; 95% CI, 0.16, 0.62; p = 0.0008) than RFA/CA; the other outcomes were not significantly different. In subgroup analyses, MWA resulted to have fewer overall complications than RFA (OR = 0.60; 95% CI, 0.38, 0.97; p = 0.04) and CA (OR = 0.49; 95% CI, 0.28, 0.85; p = 0.01); moreover, MWA was associated with fewer recurrences than CA (OR = 0.30; 95% CI, 0.11, 0.84; p = 0.02). In T1a renal tumors subgroup analysis, the outcomes were not significantly different.

CONCLUSIONS

MWA is an ablative procedure as effective and safe as RFA or CA for the treatment of renal tumors.

A three-dimensional renal tumor anatomy and intrarenal relationship nephrometry (ADDD) for robot-assisted partial nephrectomy : 3D-CT based nephrometry for RAPN

OBJECTIVE

To develop a 3D scoring system of tumor anatomy and intrarenal relationship for assessing surgical complexity and outcomes of robot-assisted partial nephrectomy (RAPN).

METHODS

We prospectively enrolled patients with a renal tumor who had a 3D model and underwent RAPN between Mar 2019 and Mar 2022. The ADDD nephrometry consisted of the contact surface area between tumor and parenchyma (A), the depth of tumor invasion into the renal parenchyma (D1), the distance from tumor to the main intrarenal artery (D2), and to the collecting system (D3). The primary outcomes included perioperative complication rate and trifecta outcome (WIT ≤ 25 min, negative surgical margins, and no major complications).

RESULTS

We enrolled a total of 301 patients. The mean tumor size was 2.93 ± 1.44 cm. There were 104 (34.6%) patients, 119 (39.5%) patients, and 78 (25.9%) patients in the low-, intermediate-, and high-risk groups, respectively. Each point increase in the ADDD score increased the risk of complications [hazard ratio (HR) 1.501]. A lower grade indicated a lower risk of failed trifecta (HR low group 15.103, intermediate group 9.258) and renal function damage (HR low risk 8.320, intermediate risk 3.165) compared to the high-risk group. The AUC of ADDD score and grade were 0.738 and 0.645 for predicting major complications, 0.766 and 0.714 for predicting trifecta outcome, and 0.746 and 0.730 for predicting postoperative renal function reservation.

CONCLUSION

The 3D-ADDD scoring system shows the tumor anatomy and its intraparenchymal relationships and has better efficacy in predicting surgical outcomes of RAPN.

The value of enhanced multiparameteric MRI diagnostic model for preoperatively predicting surgical methods of inferior vena cava in patients with renal tumors and inferior vena cava tumor thrombus

BACKGROUND

Inferior vena cava tumor thrombus (IVCTT) invading the IVC wall majorly affects the surgical method choice and prognosis in renal tumors. Enhanced multiparameteric MRI plays an important role in preoperative evaluation. In this work, an MRI-based diagnostic model for IVCTT was established so as to guide the preoperative decisions.

METHODS

Preoperative MR images of 165 cases of renal tumors with IVCTT were retrospectively analyzed, and imaging indicators were analyzed, including IVCTT morphology and Mayo grade, IVCTT diameter measurements, bland thrombosis, primary MRI-based diagnosis of renal tumor, and involvement of contralateral renal vein. The indicators were analyzed based on intraoperative performance and resection scope of the IVC wall. Multivariate logistic regression analysis was used to establish the diagnostic model.

RESULTS

The morphological classification of the IVCTT, primary MRI-based diagnosis of renal tumors, maximum transverse diameter of IVCTT, and length of the bland thrombus were the main indexes predicting IVC wall invasion. The MRI-based diagnostic model established according to these indexes had good diagnostic efficiency. The prediction probability of 0.61 was set as the cutoff value. The area under the curve of the test set was 0.88, sensitivity was 0.79, specificity was 0.85, and prediction accuracy was 0.79 under the optimal cutoff value.

CONCLUSION

The preoperative MRI-based diagnostic model could reliably predict IVC wall invasion, which is helpful for better prediction of IVC-associated surgical operations.

Metastatic rectal neuroendocrine tumor to kidney, pancreas, and bone following renal tumor resected with robot-assisted laparoscopic partial nephrectomy

Neuroendocrine tumor (NET) is a rare tumor commonly found in the gastrointestinal tract and lungs and rarely originates from and metastasizes to the kidney. We report a case of a 66-year-old man with metastatic rectal NET to the kidney, pancreas and bone following the resection of renal tumor with robot-assisted partial nephrectomy (RAPN). A rectal tumor of 10mm in diameter had been endoscopically resected and diagnosed NET with positive surgical margin 9 years before RAPN. Somatostatin receptor (SSR) scintigraphy revealed the other two metastases postoperatively, therefore is an effective tool to detect primary and metastatic sites of NETs.

The role of warm ischemia time on functional outcomes after robotic partial nephrectomy: a radionuclide renal scan study from the clock randomized trial

PURPOSE

To evaluate the relationship between warm ischemia time (WIT) duration and renal function after robot-assisted partial nephrectomy (RAPN).

METHODS

The CLOCK trial is a phase 3 randomized controlled trial comparing on- vs off-clamp RAPN. All patients underwent pre- and postoperative renal scintigraphy. Six-month absolute variation of eGFR (AV-GFR), rate of relative variation in eGFR over 25% (RV-GFR > 25), absolute variation of split renal function (SRF) at scintigraphy (AV-SRF). The relationships WIT/outcomes were assessed by correlation graphs and then modeled by uni- and multivariable regression.

RESULTS

324 patients were included (206 on-clamp, 118 off-clamp RAPN). Correlation graphs showed a threshold on WIT equal to 10 min. The differences in outcome measures between cases with WIT < vs ≥ 10 min were: AV-GFR - 3.7 vs - 7.5 ml/min (p < 0.001); AV-SRF - 1% vs - 3.6% (p < 0.001); RV-GFR > 25 9.3% vs 17.8% (p = 0.008). Multivariable models found that AV-GFR was related to WIT ≥ 10 min (regression coefficient [RC] - 0.52, p = 0.019), age (RC - 0.35, p = 0.001) and baseline eGFR (RC - 0.30, p < 0.001); RV-GFR > 25 to WIT ≥ 10 min (odds ratio [OR] 1.11, p = 0.007) and acute kidney injury defined as > 50% increase in serum creatinine (OR 19.7, p = 0.009); AV-SRF to WIT ≥ 10 min (RC - 0.30, p = 0.018), baseline SRF (RC - 0.76, p < 0.001) and RENAL score (RC - 0.60. p = 0.028). The main limitation was that the CLOCK trial was designed on a different endpoint and therefore the present analysis could be underpowered.

CONCLUSIONS

Up to 10 min WIT had no consequences on functional outcomes. Above the 10-min threshold, a statistically significant, but clinically negligible impact was found.

Case report: Congenital mesoblastic nephroma

INTRODUCTION AND IMPORTANCE

Congenital mesoblastic nephroma is a common benign renal tumor that mainly affects infants below the age of six months (Daskas et al., 2002). Identifying the pathology type is crucial for determining the appropriate plan of action and predicting the patient's prognosis.

CASE PRESENTATION

A one-day-old Hispanic neonate was referred for surgical evaluation after detecting a LUQ mass. Ultrasound imaging revealed a heterogenous solid mass that infiltrated the hilum of the left kidney. The patient underwent a left radical nephrectomy, and the pathology results indicated that the mass was consistent with the classic type of congenital mesoblastic nephroma. The patient will be closely monitored by nephrology with frequent abdominal ultrasounds.

CLINICAL DISCUSSION

The case describes a one-day-old female baby with an asymptomatic LUQ abdominal mass, which was diagnosed as mesoblastic nephroma. The baby was born full-term with no significant medical history, and after experiencing hypertensive episodes, she underwent a left radical nephrectomy to remove the tumor. Pathology confirmed mesoblastic nephroma, classic type, and the patient was diagnosed with stage I disease since the tumor was entirely resected with no renal vessel involvement. Follow-up ultrasounds were recommended to monitor for recurrence, and chemotherapy may be considered if recurrence occurs (Pachl et al., 2020). Calcium and renin levels should also be monitored (Bendre et al., 2014).

CONCLUSION

Although congenital mesoblastic nephroma is typically benign, patients require ongoing monitoring for potential paraneoplastic syndromes. Furthermore, certain types of mesoblastic nephroma can progress to malignancy, necessitating close follow-up during the first few years of life.

Intraoperative MRI-derived volumetric ablation margins and initial correlation with local outcome after MRI-guided cryoablation of renal tumors

PURPOSE

To assess volumetric ablation margins derived from intraoperative pre- and post-ablation MRI after magnetic resonance imaging (MRI)-guided percutaneous cryoablation of renal tumors and explore its correlation with local treatment success.

METHODS

Retrospective analysis was performed on 30 patients (mean age 69y) who underwent percutaneous MRI-guided cryoablation between May 2014 and May 2020 for 32 renal tumors (size: 1.6-5.1 cm). Tumor and ice-ball volumes were segmented on intraprocedural pre- and post-ablation MR images using Software Assistant for Interventional Radiology (SAFIR) software. After MRI-MRI co-registration, the software automatically quantified the minimal treatment margin (MTM),defined as the smallest 3D distance between the tumor and ice-ball surface. Local tumor progression (LTP) after cryoablation was assessed on follow-up imaging.

RESULTS

Median follow-up was 16 months (range: 1-58). Local control after cryoablation was achieved in 26 cases (81%) while LTP occurred in 6 (19%). The intended MTM of ≥5 mm was achieved in 3/32 (9%) cases. Median MTM was significantly smaller for cases with (- 7 mm; IQR:-10 to - 5) vs. without LTP (3 mm; IQR:2 to 4) (P < .001). All cases of LTP had a negative MTM. All negative treatment margins occurred in tumors > 3 cm.

CONCLUSIONS

Determination of volumetric ablation margins from intraoperative MRI was feasible and may be useful in predicting local outcome after MRI-guided renal cryoablation. In our preliminary data, an intraoperative MRI-derived minimal margin extending at least 1 mm beyond the MRI-visible tumor led to local control and this was more difficult to achieve in tumors > 3 cm. Ultimately, online margin analysis may be a valuable tool to intraoperatively assess therapy success, but larger prospective studies are needed to establish a reliable threshold for clinical use.

Robotic-assisted partial nephrectomy: single-layer cortical renorrhaphy is associated with reduced rate of renal artery pseudoaneurysm compared to double-layer renorrhaphy

The study compares the outcome of patients who underwent single-layer outer cortical renorraphy (SLOCR) and double-layer cortical renorraphy (DLR) in our institution. The retrospective analysis of 181 patients who underwent RAPN was performed. Propensity score matching was accomplished on 67 patients using age, BMI, size, distance from collecting system, hilar location and pathological stage. Intraoperative factors assessed included warm ischemia time, renorraphy time, blood loss and operative duration (Levey et al. in Clin Chem 53:766-772, 2007) Post-operative hospital stay, complications like renal artery pseudoaneurysm (RAP), hemorrhage, urine leak and reduction in eGFR were measured. The 67 patients in SLOCR group were compared with similar number in the DLR group using propensity score matching. Warm ischemia time (P < .001), renorraphy time (P < .001) and symptomatic pseudoaneurysm (RAP) rate (P < .001) were significantly less in SLOCR group. SLOCR is associated with reduced rate of symptomatic post-operative RAP.

Recognizing pathology of renal tumor from macroscopic cross-section image by deep learning

OBJECTIVES

This study aims to develop and evaluate the deep learning-based classification model for recognizing the pathology of renal tumor from macroscopic cross-section image.

METHODS

A total of 467 pathology-confirmed patients who received radical nephrectomy or partial nephrectomy were retrospectively enrolled. The experiment of distinguishing malignant and benign renal tumor are conducted followed by performing the multi-subtypes classification models for recognizing four subtypes of benign tumor and four subtypes of malignant tumors, respectively. The classification models used the same backbone networks which are based on the convolutional neural network (CNN), including EfficientNet-B4, ResNet-18, and VGG-16. The performance of the classification models was evaluated by area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. Besides, we performed the quantitative comparison among these CNN models.

RESULTS

For the model to differentiate the malignant tumor from the benign tumor, three CNN models all obtained relatively satisfactory performance and the highest AUC was achieved by the ResNet-18 model (AUC = 0.9226). There is not statistically significance between EfficientNet-B4 and ResNet-18 architectures and both of them are significantly statistically better than the VGG-16 model. The micro-averaged AUC, macro-averaged sensitivity, macro-averaged specificity, and micro-averaged accuracy for the VGG-16 model to distinguish the malignant tumor subtypes achieved 0.9398, 0.5774, 0.8660, and 0.7917, respectively. The performance of the EfficientNet-B4 is not better than that of VGG-16 in terms of micro-averaged AUC except for other metrics. For the models to recognize the benign tumor subtypes, the EfficientNet-B4 ranked the best performance, but had no significantly statistical difference with other two models with respect to micro-averaged AUC.

CONCLUSIONS

The classification results were relatively satisfactory, which showed the potential for clinical application when analyzing the renal tumor macroscopic cross-section images. Automatically distinguishing the malignant tumor from benign tumor and identifying the subtypes pathology of renal tumor could make the patient-management process more efficient.

Nephrometric scoring system: Recent advances and outlooks

A nephrometry scoring system is a key standard to evaluate the feasibility of partial nephrectomy (PN). Whether based on two-dimensional or three-dimensional images, simplicity, effectiveness, and practicality are the keys to the nephrometric scoring system. Since the emergence of RENAL score in 2009, numerous scoring systems based on different anatomical parameters are established to seek accurately and few parameters to assess the risk of PN and complications. This study aimed to achieve a three-game winning streak in PN more easily and efficiently (negative resection margin, maximum preservation of normal nephron function, and avoiding short-term and long-term complications). Using PubMed, we counted 28 kinds of nephrometric scoring systems. We considered only English literatures published and excluded editorials, commentaries, and meeting abstracts. To the best of our knowledge, this is to date and most comprehensive summary as well as an outlook of the nephrometric scoring system.

Evaluation of prognostic factors and treatment options for renal angiosarcoma: A retrospective analysis of 113 reported cases

BACKGROUND

Primary renal angiosarcoma (PRA) is an extremely rare and aggressive neoplasm. Indeed, due to its rarity, established clinical guidelines for PRA have not yet been established. In this study, we attempted to investigate its prognostic factors and treatment options.

METHODS

We systematically searched for articles describing PRA that had been published up until December 2021. The final cohort included 113 patients in 103 articles. The starting point of this study was the time of diagnosis and the end point was the time of recurrence and disease-specific mortality.

RESULTS

Metastasis at diagnosis was associated with poorer disease-specific survival (DSS) (p = 0.001). Tumors of more than 5 cm had poorer DSS than tumors of 5 cm or less (p < 0.001). Multivariate analysis demonstrated that primary metastatic status, and tumor size were independent prognostic factors. In cases of localized PRA, tumor sizes exceeding 5 cm had also prognostic significance for recurrence-free survival (RFS) and DSS. Surgical margins, postoperative radiation, and postoperative systemic therapy were not associated with prognoses. However, in a subgroup analysis of tumors exceeding 5 cm, postoperative radiation therapy improved RFS and DSS (p = 0.022 and p = 0.031, respectively). In cases of metastatic PRA, systemic therapy improved DSS (p < 0.001).

CONCLUSION

We identified several prognostic factors for PRA. Among them, primary metastatic status and tumor size exceeding 5 cm were selected as independent prognostic factors. Postoperative radiation therapy for large, localized PRA and systemic therapy for recurrent and metastatic PRA might be a treatment option.

Robot-assisted partial nephrectomy: Can retroperitoneal approach suit for renal tumors of all locations?-A large retrospective cohort study

BACKGROUND

This study aimed to explore the appropriate location of renal tumors for retroperitoneal approach.

MATERIALS AND METHODS

We retrospectively analyzed 1040 patients with renal tumor who were treated at our institution from Janurary 2015 to June 2020 and had underwent retroperitoneal robotic assisted-laparoscopic partial nephrectomy (rRAPN). Clinical features and postoperative outcomes were evaluated.

RESULTS

Patients with incomplete data were excluded, and we included 896 patients in total. The median tumor size was 3.0 (range: 0.8-10.0) cm. The median RENAL Nephrometry Score was 7 (range: 4-11), and the median PADUA Nephrometry Score was 8 (range: 6-14). The median surgical time was 120 min, and the median warm ischemia time was 18 min. The median estimated blood loss was 50 ml. The follow-up time was 20.2 (range: 12-69) months. The mean change of eGFR 1 year after operation was 14.6% ± 19.0% compared with preoperative estimated glomerular filtration rate (eGFR). When compared the tumor at different locations, as superior or inferior pole, anterior of posterior face of kidney, there were no significant differences of intra- and post-operative outcomes such as surgical time, warm ischemia time, estimated blood loss, removal time of drainage tube and catheter, postoperative feeding time and hospital stay, and changes of eGFR one year after surgery. We also compared tumors at special locations as endophytic or exophytic, anterior of posterior hilus of kidney, there were no significant differences in surgical time, warm ischemia time, estimated blood loss and changes of eGFR. There was no significant difference in intraoperative features and postoperative outcomes when tumor larger than 4 cm was located at different positions of kidney. Though the surgical time was longer when BMI ≥ 28 (132.6 min vs. 122.5 min, p = 0.004), no significant differences were observed in warm ischemia time, estimated blood loss, changes in eGFR. Twenty-seven patients (3.0%) had tumor progression, including 8 (0.9%) recurrence, 19 (2.1%) metastasis, and 9 (1.0%) death.

CONCLUSION

Retroperitoneal approach for RAPN has confirmed acceptable intra- and postoperative outcomes and suits for renal tumors of all different locations. Large tumor size and obesity are not contraindications for rRAPN.

Percutaneous Microwave Ablation is Comparable to Cryoablation for the Treatment of T1a Renal Masses: Results From a Cross-Sectional Study

INTRODUCTION

Percutaneous microwave ablation (MWA) of renal masses (RM) is still considered experimental as opposed to established procedures such as cryoablation (CA). We aimed to compare perioperative, functional and oncological outcomes of patients with RM treated with CA and MWA.

MATERIALS AND METHODS

Data from 116 (69.9%) and 50 (30.1%) patients treated with CA and MWA for RM were analyzed. Patients' demographics and perioperative data were collected including nephrometry scores, complications, pre- and postprocedural renal function. Tumor persistence and recurrence were recorded. Descriptive statistics compared functional outcomes between groups. Cox regression analyses tested risk factors associated with recurrence.

RESULTS

Groups were similar in terms of RM diameter, nephrometry scores and histology distribution. Median follow-up was 26 (13-46) and 24 (14-36) months for CA and MWA, respectively. The rate of overall (36.2% for CA vs. 24% for MWA, P= .1) and major (Clavien ≥ 3a) complications (1.7% vs. 5.4%, P = .1) were similar among groups. The median decline of renal function after 6 months follow-up did not differ between CA and MWA (P = .8). Tumor persistence [4.3% vs. 12%] and recurrence [9.5% and 7.1%] rates were similar for CA and MWA. Three years recurrence free and overall survival were 91% versus 95% (log-rank P = .77) and 80 versus 88% (log-rank P = .23) in the CA and MWA groups, respectively. At Cox analysis no predictors were found associated with recurrence.

CONCLUSION

Despite being considered still experimental, MWA showed comparable outcomes relative to CA in terms of safety, preservation of renal function and oncological efficacy.

Predicting Oncologic Outcomes in Small Renal Tumors

BACKGROUND

Most patients diagnosed with renal cancer today present with small renal masses (SRMs). Although these patients have a low risk of dying from their disease and many are followed with active surveillance protocols, a small subset of renal cell carcinomas (RCCs) behave aggressively. Knowledge regarding features of aggressive behavior would enable better adoption of active surveillance strategies among these patients.

OBJECTIVE

We sought to improve prognostic models to predict metastasis-free survival after nephrectomy through focused analyses of clinicopathologic characteristics of SRMs associated with adverse outcomes.

DESIGN, SETTING, AND PARTICIPANTS

We identified consecutive patients with surgically resected SRMs (≤4 cm) at the University of Texas Southwestern Kidney Cancer Program between 1998 and 2020. In addition, we evaluated the ability of SRMs to form tumors when implanted in mice, an indicator of tumor aggressiveness.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We examined the clinicopathologic factors associated with metastasis including prospectively performed BAP1 immunohistochemistry at our Clinical Laboratory Improvement Amendments laboratory. Multivariable Cox proportional hazard regression was used to predict metastasis-free survival.

RESULTS AND LIMITATIONS

A total of 3900 evaluable nephrectomies (from 3674 ethnically diverse patients) were identified, of which 1984 (51%) were SRMs including 1720 RCC. Of these patients with RCC (SRMRCC), 1576 did not have synchronous or metachronous larger RCCs and among these, 37 (2%) developed metastases. SRMRCC that metastasized were significantly enriched for aggressive morphologic phenotypes and engrafted in mice at comparable rates as larger metastatic tumors. BAP1 loss remained significantly associated with metastasis-free survival after accounting for TNM (tumor-node-metastasis) stage and SSIGN (stage, size, grade, and necrosis) score in multivariable analysis.

CONCLUSIONS

We identified clinicopathologic features that influence metastasis-free survival for patients with SRMRCC. If validated independently, these data should assist with patient prognosis and help with active surveillance strategies.

PATIENT SUMMARY

We report the identification of features of aggressiveness in small renal tumors that influence the likelihood of metastases after surgery.

Renal involvement of lymphomas proven by kidney biopsy: report of 10 cases from a tertiary care center and comparison with the literature

Lymphomas localized in the kidney are a rare entity that may be challenging to diagnose. We analyzed data from 10 patients with renal involvement of lymphoma diagnosed between 2009 and 2019 on fine needle biopsy from our tertiary center, and compared these with findings of 160 cases reported in the literature. Diffuse large B-cell lymphoma was the main histology subtype (40 and 38% in our sample and in the literature, respectively), followed by low-grade B-cell lymphomas, mostly from the marginal zone (MZ). Altogether, 106 patients had urological inaugural symptoms and 64 had general symptoms. Patients with urological presentation more often had renal masses than diffuse infiltration (p < 0.001), unilateral tumors (p = 0.0036) and low-grade B-cell lymphomas (17 vs 6%, p = 0.043). In both groups, nearly one-fourth of patients had diffuse (stage IV) lymphomas. Overall survival did not differ by the presence of urological/systemic symptoms, stage or aggressive lymphoma status. Notably, 3 of 10 patients from our series had MZ lymphomas associated with primary Sjögren syndrome revealed by acute kidney injury, including one where the autoimmune disease was detected. Lymphoproliferative disorders localized in the kidney are a challenging condition that can lead to detection of aggressive or diffuse lymphomas.

Giant renal schwannoma with obvious hemorrhage and cystic degeneration: a case report and literature review

BACKGROUND

Renal schwannomas are very rare and are usually benign. Its clinical symptoms and imaging features are nonspecific, and the diagnosis is usually confirmed by pathology after surgical resection.

CASE PRESENTATION

A 46-year-old Chinese female was admitted to the hospital with right flank pain that had persisted for the six months prior to admission. This pain had worsened for 10 days before admission, and dyspnea occurred when she was supine and agitated. A right abdominal mass could be palpated on physical examination. Computed tomography and magnetic resonance imaging examinations revealed a large, nonenhanced, cystic and solid mass in the right kidney. The patient received radical nephrectomy for the right kidney. The diagnosis of schwannoma was confirmed by pathological examination.

CONCLUSIONS

We report a case of a large renal schwannoma with obvious hemorrhage and cystic degeneration, which can be used as a reference for further study.

The application of full-size three-dimensional individual printed model combined with three-dimensional digital demonstration can facilitate patient's preoperative comprehension to robotic-assisted laparoscopic partial nephrectomy

BACKGROUND

In this study, it was aimed to evaluate the feasibility and effectiveness of full-size three-dimensional individual printed model (3D-IPM) based on computerized tomography (CT) reconstruction combined with 3D individual digital models (3D-IDMs) for improving the patient's and their families' comprehension levels of robotic-assisted laparoscopic partial nephrectomy (RALPN) preoperatively.

METHODS

Between January 2020 and January 2021, 37 patients underwent RALPN in our institution. 3D individual digital models (3D-IDMs) were reconstructed based on the data of computerized tomography (CT) scanning and full-size 3D-IPMs were fabricated correspondingly. For each patient and his/her closest accompanying immediate family member (CAIFM) (spouse or son/daughter), two semi-structured conversations were held by using CT films (1st conversation) and 3D-IPM combined with 3D-IDM demonstration (2nd one) respectively. The preoperative levels of comprehension were evaluated quantitatively by using a self-made preoperative comprehending score (PCS) in the patients and CAIFMs.

RESULTS

All the fabrications of full-size 3D-IPMs and all the operations were technically successful. The total PCS elevated significantly by presenting 3D-IPM combined with 3D-IDM demonstration compared with CT films (42.5 vs 35.5 in patients, P < 0.001; 42.9 vs 35.8 in CAIFMs, P < 0.001). Sub-PCSs in the evaluating aspects of renal anatomy, mass characteristics, the upcoming RALPN procedure, potential complication risks, and prognosis also showed a uniformed climbing pattern with the assistance of 3D-IPM+3D-IDM.

CONCLUSION

The application of 3D-IPM presentation combined with 3D-IDM demonstration can improve the preoperative comprehension of patient and CAIFM to RALPN with more direct-viewing and verisimilar presentation, and can be used in RALPN patient education for increasing patients' and their families' cognitive empowerment.

“Zero ischemia” laparoscopic partial nephrectomy by high-power GreenLight laser enucleation for renal carcinoma: A single-center experience

BACKGROUND

Laparoscopic partial nephrectomy has been widely used in renal cell carcinoma treatment. The efficacy of GreenLight laser on Laparoscopic partial nephrectomy is still unknown.

AIM

To present the first series of laparoscopic partial nephrectomy (LPN) by GreenLight laser enucleation without renal artery clamping. Due to the excellent coagulation and hemostatic properties of the laser, laser-assisted LPN (LLPN) makes it possible to perform a “zero ischemia” resection.

METHODS

Fifteen patients with T1a exogenous renal tumors who received high-power GreenLight laser non-ischemic LPN in our hospital were retrospectively analyzed. All clinical information, surgical and post-operative data, complications, pathological and functional outcomes were analyzed.

RESULTS

Surgery was successfully completed in all patients, and no open or radical nephrectomy was performed. The renal artery was not clamped, leading to no ischemic time. No blood transfusions were required, the average hemoglobin level ranged from 96.0 to 132.0 g/L and no postoperative complications occurred. The mean operation time was 104.3 ± 8.2 min. The postoperative removal of negative pressure drainage time ranged from 5.0 to 7.0 d, and the mean postoperative hospital stay was 6.5 ± 0.7 d. No serious complications occurred. Postoperative pathological results showed clear cell carcinoma in 12 patients, papillary renal cell carcinoma in 2 patients, and hamartoma in 1 patient. The mean creatinine level was 75.0 ± 0.8 μmol/L (range 61.0-90.4 μmol/L) at 1 mo after surgery, and there were no statistically significant differences compared with pre-operation (P > 0.05). The glomerular filtration rate ranged from 45.1 to 60.8 mL/min, with an average of 54.0 ± 5.0 mL/min, and these levels were not significantly different from those before surgery (P > 0.05).

CONCLUSION

GreenLight laser has extraordinary cutting and sealing advantages when used for small renal tumors (exogenous tumors of stage T1a) during LPN. However, use of this technique can lead to the generation of excessive smoke.

Application and clinical efficacy of modified early unclamping technique in robot-assisted laparoscopic partial nephrectomy

OBJECTIVE

To investigate the clinical safety and efficacy of a modified early unclamping technique in robot-assisted laparoscopic partial nephrectomy (RAPN).

METHODS

The clinical data of 38 patients with renal tumors who underwent the modified early unclamping technique in RAPN surgery admitted to the Department of Urology, the Third People's Hospital of Hangzhou and the First Affiliated Hospital of Nanchang University from January 2018 to April 2021 were retrospectively analyzed. The control group consisted of 78 patients with renal tumors who underwent standard clamping during the RAPN surgery completed by the same surgeon during the same period. The perioperative-related indicators and postoperative renal function recovery were analyzed and compared between the two groups.

RESULTS

All patients (n = 116) finished the RAPN successfully, and none were transferred to radical or open surgery in either group. The warm ischemia time in the modified early unclamping group was significantly lower than that in the standard clamping group (P < 0.001). After surgery, the renal function index at each time point in the modified early unclamping group was higher than that in the standard clamping group; renal function gradually returned to near preoperative levels after 3 months in both groups. Postoperative follow-up showed no tumor recurrence or metastasis.

CONCLUSION

The application of a modified early unclamping technique in RAPN surgery is safe and feasible. Compared with standard clamping, modified early unclamping can significantly shorten the warm ischemia time of kidneys without increasing the volume of intraoperative blood loss and complications, which helps to protect the postoperative renal function of patients.

The comparative study of color doppler flow imaging, superb microvascular imaging, contrast-enhanced ultrasound micro flow imaging in blood flow analysis of solid renal mass

Purposes

To evaluate the value of Color Doppler Flow Imaging (CDFI), Superb Microvascular Imaging (SMI) and Contrast-enhanced Ultrasound Microflow Imaging (MFI) in display the microvascular blood flow signals in renal solid lesions.

Methods

142 patients with 144 renal masses were examined by CDFI, SMI and MFI simultaneously. We compared the difference of blood flow grading and vascular architecture based on CDFI, SMI and MFI.

Results

The blood flow signals detection rates of CDFI, SMI and MFI were 78.5% (113/144), 88.9% (128/144) and 93.8% (135/144), respectively. Concentrated on blood flow grading, The coincidence rates of CDFI and SMI were 64.58% (93/144) and 81.25% (117/144) referring to MFI, respectively. Blood flow grade 2–3 in CDFI is significantly lower than SMI(x² = 5.557, P = 0.018) and MFI (x² = 10.165, P = 0.001). Whereas there was no significant difference between SMI and MFI (x² = 2.372, P = 0.499). Concentrated on vascular architecture, the coincidence rates of CDFI and SMI were 56.25% (81/144) and 75.69% (109/144) referring to MFI, respectively. Vascular architecture type IV and V in CDFI was significantly lower than SMI (x² = 18.217, P < 0.001) and MFI (x² = 29.518, P < 0.001). Whereas there was no significant difference between SMI and MFI (x² = 3.048, P = 0.550). The sensitivity and specificity of CDFI, SMI and MFI in the diagnosis of renal mass were 61.29% and 90.20%, 79.57% and 88.24%, 88.17% and 84.31% respectively. The areas under the ROC curve of the three were 0.757, 0.839 and 0.862, respectively. There was a statistically significant difference between CDFI and MFI (Z = 3.687, P = 0.0002), while there was no statistically significant difference between SMI and MFI (Z = 1.167, P = 0.2431).

Conclusion

SMI and MFI are superior to CDFI in showing blood flow signals in renal solid masses, and it can perform blood flow and vascular architecture more accurately.

Advances in knowledge

SMI is similar to MFI in its ability to display fine vessels and diagnostic efficiency, and has application value in the diagnosis and differential diagnosis of renal solid masses.

Validation of the modified Bosniak classification system to risk stratify pediatric cystic renal masses: An international, multi-site study from the pediatric urologic oncology working group of the societies for pediatric urology

BACKGROUND

Pediatric cystic renal lesions are challenging to manage as little is known about their natural course. A modified Bosniak (mBosniak) classification system has been proposed for risk stratification in pediatric patients that takes ultrasound (US) and/or computed tomogram (CT) characteristics into account. However, literature validating this system remains limited.

OBJECTIVE

To determine if the mBosniak classification system correlates with pathologic diagnoses. The hypothesis is that mBosniak classification can stratify the risk of malignancy in children with renal cysts.

STUDY DESIGN

Patients treated for cystic renal masses with available imaging and pathology between 2000 and 2019 from five institutions were identified. Clinical characteristics and pathology were obtained retrospectively. Characteristics from the most recent US, CT, and/or magnetic resonance imaging (MRI) were recorded. Reviewers assigned a mBosniak classification to each scan. mBosniak scores 1/2 were considered low-risk and 3/4 high-risk. These groups were compared with pathology (classified as benign, intermediate, malignant). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were calculated to assess this categorization as a screening tool to guide surgical intervention. Agreement between imaging modalities was also explored.

RESULTS

99 patients were identified. High-risk imaging findings were correlated with malignant or intermediate pathology with a sensitivity of 88.3%, specificity of 84.6%, PPV of 89.8%, NPV of 82.5%, +LR of 5.7, and -LR of 0.14. The sensitivity for detecting malignant lesions only was 100%. There was substantial agreement between US/CT (n = 55; κ = 0.66) and moderate agreement between US/MRI (n = 20; κ = 0.52) and CT/MRI (n = 13; κ = 0.47).

DISCUSSION

The mBos classification system is a useful tool in predicting the likelihood of benign vs. intermediate or malignant pathology. The relatively high sensitivity and specificity of the system for prediction of high-risk lesions makes this classification applicable to clinical decision making. In addition, all malignant lesions were accurately identified as mBosniak 4 on imaging. This study adds substantial data to the relatively small body of literature validating the mBosniak system for risk stratifying pediatric cystic renal lesions.

CONCLUSIONS

Pediatric cystic renal lesions assigned mBosniak class 1/2 are mostly benign, whereas class 3/4 lesions are likely intermediate or malignant pathology. We observed that the mBosniak system correctly identified pathology appropriate for surgical management in 88% of cases and did not miss malignant pathologies. There is substantial agreement between CT and US scans concerning mBos classification.

Imaging features and differences among the three primary malignant non-Wilms tumors in children

Background

The pathology, treatment and prognosis of malignant non-Wilms tumors (NWTs) are different, so it is necessary to differentiate these types of tumors. The purpose of this study was to review the clinical and imaging features of malignant NWTs and features of tumor metastasis.

Methods

We retrospectively analyzed the CT images of 65 pediatric patients with NWTs from March 2008 to July 2020, mainly including clear cell sarcoma of the kidney (CCSK), malignant rhabdomyoma tumor of the kidney (MRTK) and renal cell carcinoma (RCC). Available pretreatment contrast-enhanced abdominal CT examinations were reviewed. The clinical features of the patients, imaging findings of the primary mass, and locoregional metastasis patterns were evaluated in correlation with pathological and surgical findings.

Results

The study included CCSK (22 cases), MRTK (27 cases) and RCC (16 cases). There were no significant differences observed among the sex ratios of CCSK, MRTK and RCC (all P > 0.05). Among the three tumors, the onset age of MRTK patients was the smallest, while that of RCC patients was the largest (all P < 0.05). The tumor diameter of CCSK was larger than that of MRTK and RCC (all P < 0.001). For hemorrhage and necrosis, the proportion of MRTK patients was larger than that of the other two tumors (P = 0.017). For calcification in tumors, the proportion of calcification in RCC was highest (P = 0.009). Only MRTK showed subcapsular fluid (P < 0.001). In the arterial phase, the proportion of slight enhancement in RCC was lower than that in the other two tumors (P = 0.007), and the proportion of marked enhancement was the highest (P = 0.002). In the venous phase, the proportion of slight enhancement in RCC was lower than that in the other two tumors (P < 0.001). Only CCSK had bone metastasis. There was no liver and lung metastasis in RCC.

Conclusions

NWTs have their own imaging and clinical manifestations. CCSK can cause vertebral metastasis, MRTK can cause subcapsular effusion, and RCC tumor density is usually high and calcification. These diagnostic points can play a role in clinical diagnosis.

Impact of surgical approach and resection technique on the risk of Trifecta Failure after partial nephrectomy for highly complex renal masses

INTRODUCTION

We aimed to compare the outcomes of open vs robotic partial nephrectomy (PN), focusing on predictors of Trifecta failure in patients with highly complex renal masses.

PATIENTS AND METHODS

We queried the prospectively collected database from the SIB International Consortium, including 507 consecutive patients with cT1-2N0M0 renal masses treated at 16 high-volume referral centres, to select those with highly complex (PADUA score ≥10) tumors undergoing PN. RT was classified as enucleation, enucleoresection or resection according to the SIB score. Trifecta was defined as achievement of negative surgical margins, no acute kidney injury and no Clavien-Dindo grade ≥2 postoperative surgical complications. Multivariable logistic regression analysis was used to assess independent predictors of Trifecta failure.

RESULTS

113 patients were included. Patients undergoing open PN (n = 47, 41.6%) and robotic PN (n = 66, 58.4%) were comparable in baseline characteristics. RT was classified as enucleation, enucleoresection and resection in 46.9%, 34.0% and 19.1% of open PN, and in 50.0%, 40.9% and 9.1% of robotic PN (p = 0.28). Trifecta was achieved in significantly more patients after robotic PN (69.7% vs. 42.6%, p = 0.004). On multivariable analysis, surgical approach (open vs robotic, OR: 2.62; 95%CI: 1.11-6.15, p = 0.027) and tumor complexity (OR for each additional unit of the PADUA score: 2.27; 95%CI: 1.27-4.06, p = 0.006) were significant predictors of Trifecta failure, while RT was not. The study is limited by lack of randomization; as such, selection bias and confounding cannot be entirely ruled out.

CONCLUSIONS

Tumor complexity and surgical approach were independent predictors of Trifecta failure after PN for highly complex renal masses.

Leiomyoma as a case of renal tumor

Leiomyoma is a benign tumor originate from mesenchymal or connective tissue. Because of a low incidence, difficulties in differentiation from other renal tumors with imaging modalities, the definitive diagnosis of a leiomyoma is possible after examination of a specimen. We present a case of 79-years-old women with incidentally discovered renal tumor in CT scan. Because of the small size of a tumor, patient was informed about possibility of active surveillance. Partial nephrectomy was performed with a histopathologic diagnosis of renal leiomyoma. After 6 months of a follow-up, patient is found to be asymptomatic and free of disease.

[Epithelioid angiomyolipoma of the kidney after successfully treated malignant melanoma]

Hintergrund

Die Therapie der epitheloiden Angiomyolipome (eAML) kann eine Herausforderung darstellen, da bei dieser sehr seltenen Unterform der gutartigen mesenchymalen Angiomyolipome anders als bei den klassischen Angiomyolipomen bei bis zu 30 % der Fälle Lymphknotenmetastasen, lokale Rezidive und Fernmetastasen auftreten.

Ziel der Arbeit

Wir berichten hier nach unserer Recherche erstmals in Deutschland von einem Fall von eAML nach stattgehabtem malignem Melanom.

Material und Methoden

Neben der Klinik und Histologie wird die genetische Untersuchung des Tumorgewebes dargestellt.

Ergebnisse

Es fand sich eine somatische, trunkierende Mutation des TSC2-Gens („tuberous sclerosis complex“) im Angiomyolipom.

Schlussfolgerung

Die Beziehung zu verwandten Tumorentitäten in der histologischen Diagnostik wird dargestellt und eine mögliche Rolle der genetischen Diagnostik für die Therapieplanung diskutiert.

Repeat Percutaneous Radiofrequency Ablation of T1 Renal Cell Carcinomas is Safe in Patients with Von Hippel-Lindau Disease

Purpose

Patients with Von Hippel-Lindau disease often develop multifocal, metachronous renal cell carcinomas which require therapy. The purpose of this retrospective single-center study is to evaluate the outcomes of radiofrequency ablation (RFA) in the treatment of renal cell carcinomas in patients with Von Hippel-Lindau disease.

Materials and Methods

9 patients (4 male, 5 female, 47.9 ± 10.7 y/o) with Von Hippel-Lindau disease underwent 18 CT-guided percutaneous RFA procedures for the treatment 21 renal cell carcinomas (largest diameter: 32.9 ± 8.6 mm, cT1a: 16, cT1b: 5). Seven patients were previously treated either by partial or radical nephrectomy. Technical success, effectiveness, safety, progression-free survival, overall survival and tumor characteristics were analyzed.

Results

All RFA procedures were technically successful without major complications. There were 5 minor complications. No residual or recurrent tumor was seen in the ablation zone during a follow-up of 34.0 ± 18.1 months (0–58 months). No patient required dialysis during follow-up. One patient died after 63 months after the first treatment due to complications from a cerebellar hemangioblastoma. No endpoint was reached for overall or progression-free survival.

Conclusions

The results from this limited case series suggest that RFA of RCCs in patients with VHL is a safe and effective therapy, which can preserve sufficient renal function even after renal surgery.

Can preoperative renal mass biopsy change clinical practice and reduce surgical intervention for small renal masses?

INTRODUCTION

The role of renal biopsy prior to surgical intervention for a renal mass remains controversial despite the fact that for all other urological organs except the testicle, biopsy inevitably precedes treatment as is true for all other specialties dealing with solid masses (e.g. thyroid, breast, colon, liver, etc.). Accordingly, we sought to determine the impact of a routine biopsy regimen on the course of patients with cT1a lesions in comparison with a contemporary series of cT1a individuals who went directly to treatment without a preoperative biopsy.

METHODS

We analyzed a multi-institutional, prospectively maintained database of patients who underwent an office-based, ultrasound-guided, renal mass biopsy (RMB) for a cT1a renal mass (i.e. ≤4cm in largest dimension). Controls were selected from all patients in the database who had a cT1a renal lesion but did not undergo RMB. Both groups were analyzed for differences in treatment modality and surgical pathology results.

RESULTS

A total of 72 RMB and 73 control patients were analyzed. The groups were similar in regards to their baseline characteristics. Overall RMB diagnostic rate was 75%. Surgical pathology revealed that excision of benign tumors was eight-fold less in the RMB cohort compared to the control group (3% vs. 23%; P < 0.001). Additionally, the rate of active surveillance in the RMB cohort was nearly three times higher at 35% vs. 14% for the controls (P < 0.001). Biopsy was concordant with surgical pathology in 97% of cases for primary histology (i.e. benign vs. malignant), 97% for histologic subtype, and 46% for low (I or II) vs. high (III or IV) grade. On multivariate analysis patients who underwent surgical intervention without preoperative RMB were 6.7 times more likely to have benign histopathology compared to patients who underwent preoperative RMB (OR 6.7, 95% CI = 0.714 - 63.626, P = 0.096). There were no procedural or post-procedural RMB complications.

CONCLUSIONS

For patients with cT1a lesions, the implementation of routine office-based RMB led to a significant decrease in the rate of surgical intervention for benign tumors. This practice also resulted in a higher rate of active surveillance for the management of renal cortical neoplasms with benign histopathology compared to a control group.

Open versus minimally-invasive surgical techniques in pediatric renal tumors: A population-level analysis of in-hospital outcomes

INTRODUCTION

Minimally-invasive surgery (MIS) has been adopted slowly in pediatric oncology. We attempted to describe contemporary national trends in MIS use; we hypothesized that adolescents (who are more likely to have relatively small renal cell carcinomas) would have a higher proportion of MIS than younger children (who are more likely to have relatively large Wilms tumors) and that this relationship would vary by region.

OBJECTIVE

To explore whether pediatric urologic oncology outcomes vary by patient age or by surgical technique.

METHODS

We queried the 1998-2014 National Inpatient Sample (NIS) and included encounters in children aged ≤ 18 y, ICD-9 diagnostic code for renal tumor, and procedure code for open or MIS partial or radical nephrectomy. All analyses used weighted descriptive statistics and outcomes are compared based on age group (</>10 y) or surgery type; Wald-Chi square test was used for differences in proportions and unadjusted weighted ANOVA was used to test for differences in means.

RESULTS

9259 weighted encounters were included; 91% were <10 years old and 50.7% were female. MIS surgery accounted for 1.8% of encounters; there was a difference in proportions by age group (1% <9 y vs. 9.9% >9 y, p < 0.01). The proportion of surgery type was similar across regions within age groups, however. Complications occurred in 13.3% of encounters; mean inpatient length of stay was 8.9 days (SD: 0.3); mean cost was $ 34,457.68 (SD: $1197.00). There was no evidence of a difference between surgery type and proportion of post-operative complications, mean inpatient length of stay or mean inpatient cost.

DISCUSSION

The admission-based, retrospective design of NIS left us unable to assess long-term outcomes, repeated admissions, or to track a particular patient across time; this is particularly relevant for oncologic variables on interest such as tumor stage or event-free survival. We were similarly limited in evaluating the effect of pre-surgical referral patterns on patient distributions.

CONCLUSION

In this preliminary descriptive analysis, MIS techniques were infrequently used in children, but there was a higher proportion of MIS use among adolescents. There were similar proportions of surgery type across geographic regions within the United States. Whether this infrequent usage is appropriate is as yet unclear given the lack of Level I evidence regarding the relative merits of MIS and open surgery for pediatric and adolescent renal tumors.

Surgical management of horseshoe kidney tumors. Literature review and analysis of two cases

INTRODUCTION

The horseshoe kidney is a rare congenital anomaly in the general population that combines renal ectopia, malrotation and abnormal vascular supply. The most frequently developed tumor in this case is renal cell carcinoma (50%). One of its main characteristics is great anatomical variation, especially in terms of vascular structures.

MATERIAL AND METHODS

We present two cases of patients with diagnosis of renal tumor in horseshoe kidneys, both treated with laparoscopic partial nephrectomy in our department. Additionally, we have carried a review of the current literature.

DISCUSSION

Indications for surgical treatment in this pathology are the same as in kidneys with normal anatomy. Traditionally, treatment has been open surgery, with heminephrectomy as surgery of choice. The current trend is to advocate nephron-sparing surgery, and the laparoscopic approach has been progressively gaining importance.

CONCLUSION

A thorough imaging study is essential for proper surgical planning.

Wilms' Tumor in Horseshoe Kidney

Wilms' tumor is the most common malignant kidney tumor found in children. The Horseshoe kidney is the most common renal fusion malformation. However, Wilms' tumor is rarely identified in horseshoe kidney patients. Multimodal treatments in Wilms' tumor can play important roles in increasing the survival rate. In this study, we report the case of a 6-year-old boy in whom a Wilms' tumor was identified in a horseshoe kidney. The tumor was successfully treated with preoperative chemotherapy, followed by surgical resection.