Rare case of stromal predominant Wilm's tumour with rhabdomyoblastic differentiation in FNAC smears.

The FNAC smear and histopathology of stromal predominant Wilm's tumour with rhabdomyoblastic Differentiation along with immunostaining in a 7-year-old male. In this paper, the diagnostic potential of FNAC in identifying rare histological variants of paediatric renal tumours is highlighted.

An Unusual Case of Extramedullary Hematopoiesis in the Right Kidney.

Extramedullary hematopoiesis (EMH) is the formation of blood cells outside the bone marrow, typically occurring in response to chronic anemia or bone marrow dysfunction. While EMH is most commonly observed in the liver, spleen, and lymph nodes, its occurrence in the kidney is exceedingly rare. In this case report, we are presenting a case of a 49-year-old male diagnosed with polycythemia vera who had an incidental right renal mass, which was histo-pathologically proven as extramedullary hematopoiesis in the right kidney mimicking lymphoma. This case underscores the importance of considering EMH in the differential diagnosis of renal masses, especially in patients with a history of myeloproliferative disorders. Early recognition and appropriate management are crucial to avoid unnecessary interventions and manage the underlying hematological condition effectively. Accurate diagnosis through histopathological examination is crucial to avoid unnecessary surgical interventions.

Significance of Charlson co-morbidity index as predictive factor for post-op complications after radical nephrectomy.

The current study planned to explore the correlation between an elevated Charlson Comorbidity Index score and post-operative complications following radical nephrectomy in patients with renal cell carcinoma. A total of 70 patients aged 30-80 years undergoing radical nephrectomy were categorised into low Charlson Comorbidity Index score <4 group A and high score >4 group B. Post-operatively, complications were noted in 21(30%) patients, with higher grades more prevalent in the group B patients (relative risk: 1.96, p=0.004). The finding underscored the importance of considering comorbidities in assessing the risk of complications following radical nephrectomy.

Laparoscopic Retrograde Nephrectomy as a Troubleshooting Technique to Prevent Open Conversion: The Technique Description With a Review of 40 Cases.

Introduction Laparoscopic nephrectomies are safe, with low complication rates in skilled hands. However, traditional approaches may be unsuitable for conditions such as post-renal abscesses, long-standing urinomas, non-functioning kidneys post-pyeloplasty, pyelolithotomies, post-partial nephrectomy recurrences, tuberculous kidneys, pyelonephritis, and redo-renal surgeries. This study describes a modified retrograde nephrectomy technique and its outcomes in 40 cases. Methods We reviewed 40 cases where the retrograde nephrectomy technique was used. Surgeons opted for this method based on intraoperative findings and initial difficulties in accessing the lower pole area. Results Traditional dissection was challenging due to adhesions in the lower pole. The retrograde technique, starting from the renal hilum, allowed early ligation of renal arteries and veins, reducing bleeding risks and facilitating safer caudal dissection. Conclusions The retrograde nephrectomy technique offers a safer and more efficient alternative for complex nephrectomies. Early vascular control minimizes hemorrhage risk, making it a valuable method in challenging renal surgeries.

Renal Endometriosis Mimics Renal Cell Carcinoma in a Hypoplastic Kidney: A Case Report.

Renal endometriosis is a rare disorder of cases of urinary tract endometriosis. A 42-year-old woman presented at our outpatient department with an incidental painless mass on her left hypoplastic kidney revealed on an abdominal ultrasound. Abdominal and pelvic examinations revealed no abnormal findings. A computed tomography (CT) scan revealed an anterolateral slightly enhanced left renal mass that measured 1.2 cm in diameter. Furthermore, CT did not reveal any evidence of abdominal or thoracic metastasis. There are a few case reports in the literature of tumors in specimens from patients who underwent nephrectomy for hypoplastic kidneys, but discriminating between benign and malignant masses is difficult unless a nephrectomy is performed. Given the radiological findings and the impaired function of the hypoplastic kidney, laparoscopic radical nephrectomy was recommended. The procedure was performed under general anesthesia without intraoperative or postoperative complications. Microscopic examination revealed several findings consistent with a diagnosis of renal endometriosis. The patient had no symptoms at her last follow-up visit. This case highlights that renal endometriosis can mimic renal cell carcinoma and awareness of this entity should be raised, as it can be asymptomatic, especially when located in a hypoplastic kidney.

Cutting-Edge Strategies for Renal Tumour-like Lesions in Granulomatosis with Polyangiitis: A Systematic Review.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is characterised by granulomatous inflammation and small-to-medium vessel necrotising vasculitis, mainly affecting respiratory tract and kidneys. Renal involvement presenting as tumour-like lesions poses diagnostic and treatment challenges. METHODS: Following the observation of a GPA patient presenting with multiple renal tumour-like lesions, we conducted a systematic literature review on MEDLINE/PubMed, EMBASE, and Cochrane databases. Data gathered from the literature were analysed to summarise the diagnostic approach, management, and outcome of renal GPA-related tumour-like lesions. RESULTS: a 49-year-old female presented with persistent constitutional symptoms and multiple bilateral renal lesions. Renal biopsy showed chronic interstitial inflammation with necrotising granulomas. Laboratory tests disclosed positive anti-proteinase 3 (PR3) anti-neutrophil cytoplasmic antibody (ANCA) leading to a final diagnosis of GPA. She was effectively treated with high-dose glucocorticoids and rituximab. Literature search yielded 41 articles, concerning 42 GPA patients with renal masses, presenting bilaterally in 23.8% of the cases. Positive PR3-ANCA was observed in 86.5% of the cases. Half of 42 patients showed kidney abnormalities. Treatment with glucocorticoids (83.3%) and immunosuppressive agents (80.9%) resulted in an overall good remission rate and favourable prognosis. CONCLUSIONS: GPA should be considered in the differential diagnoses of kidney tumour-like lesions. The diagnosis is challenging, and histological examination greatly contributes to the diagnostic work-up.

Off-clamp vs on-clamp robot-assisted partial nephrectomy: a systematic review and meta-analysis.

OBJECTIVE: To compare intra- and postoperative outcomes between off-clamp and on-clamp robot-assisted partial nephrectomy (RAPN), using data from randomised controlled trials (RCTs) or covariate-matched studies (propensity score-matched or matched-pair analysis). METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant literature review was conducted on PubMed, EMBASE, Scopus and CENTRAL for relevant studies comparing off-clamp to on-clamp RAPN. Primary outcomes were estimated blood loss, postoperative percentage decrease in estimated glomerular filtration rate (eGFR), and margin positive rate. Secondary outcomes were operative time, postoperative eGFR, length of stay, all postoperative complications, major complications, and need for transfusion. Random-effects meta-analyses were performed to generate mean differences (MDs) or odds ratios (ORs). RESULTS: A total of 10 studies (2307 patients) were shortlisted for analysis. There was no significant difference in estimated operative blood loss between off-clamp and on-clamp RAPN (MD 21.9 mL, 95% confidence interval [CI] -0.9 to 44.7 mL; P = 0.06, I2 = 58%). Off-clamp RAPN yielded a smaller postoperative eGFR deterioration (MD 3.10%, 95% CI 1.05-5.16%; P = 0.008, I2 = 13%) and lower odds of margin positivity (OR 0.62, 95% CI 0.40-0.94; P = 0.03, I2 = 0%). No significant differences were found for all secondary outcomes. CONCLUSIONS: Off-clamp and on-clamp RAPN are similarly effective approaches for selected renal masses. Within the classic trifecta of PN outcomes, off-clamp RAPN yields similar rates of perioperative complications and may possibly offer better preservation of renal function and reduced margin-positive rates.

Post-operative flank irradiation using conformal versus highly conformal radiotherapy techniques for paediatric renal tumours: Results from the French registry PediaRT.

PURPOSE: Three-dimensional conformal RT (3D-RT) techniques are gold standard for post-operative flank radiotherapy (RT) in paediatric renal tumours. Recently, highly conformal RT (HC-RT) techniques have been implemented without comparative clinical data. The main objective of this multicentre study was to compare locoregional control (LRC) in children treated either with HC-RT or 3D-RT techniques. METHODS: Patients treated with post-operative flank RT for renal tumour registered in the national cohort PediaRT between March 2013 and September 2019 were included. Treatment and follow-up data, including toxicities and outcomes, were retrieved from the database. LRC was calculated, and dose reconstruction was performed in case of an event. RESULTS: Seventy-nine patients were included. Forty patients were treated with HC-RT and 39 with 3D-RT. Median follow-up was 4.5 years. Three patients had locoregional failure (LRF; 4%). HC-RT was not associated with a higher risk of LRF. Three-year LRC were 97.4% and 94.7% in the HC-RT and 3D-RT groups, respectively. The proportion of planning target volumes receiving 95% or more of the prescribed dose did not significantly differ between both groups (HC-RT 88%; 3D-RT 69%; p = .05). HC-RT was better achieving dose constraints, and a significant mean dose reduction was observed in the peritoneal cavity and pancreas associated with lower incidence of acute gastrointestinal toxicity. CONCLUSION: LRF after post-operative flank RT for renal tumours was rare and did not increase using HC-RT versus 3D-RT techniques. Dose to the pancreas and the peritoneal cavity, as well as acute toxicity, were reduced with HC-RT compared to 3D-RT.

Renal Tumours Of Non-Clear Cell Histology; 10 Years' Experience In A Specialized Centre.

BACKGROUND: Non-clear cell renal cell carcinomas are uncommon renal tumours with diverse histologically and genetically defined entities. Due to limited clinical outcomes data, no standardized management approach can be offered to these patients. This study aimed to analyse outcomes of non clear cell renal cell carcinoma after surgical resection of localized renal tumours in our population. METHODS: Patients with renal tumours who underwent partial or radical nephrectomy at the Department of Urology, from January 2010 to December 2019 were identified and evaluated, in terms of prevalence, presentation, recurrence, and survival outcome. RESULTS: Non-clear cell tumours were found in one-fourth of the total number of nephrectomies performed during this period for renal cell carcinoma (RCC). The mean age was 50.48±14.76 years (range 18-89 years) with 57% being of the male gender. The predominant types were chromophobe RCC, papillary RCC, and sarcomatoid RCC, in all non-clear cell renal tumours. Mean Recurrence Free Survival (RFS) for all tumours was 75.26±2.7 months. The projected 5 years RFS of papillary RCC, chromophobe RCC and sarcomatoid RCC were 94.2%, 84.3% and 62.5% respectively. CONCLUSIONS: RCC of non-clear-cell histology depicts excellent survival in patients with localized renal tumours. Furthermore, sarcomatoid RCC has worse recurrence free survival followed by chromophobe RCC and papillary RCC, in our population subset.

Comparative analyses define differences between BHD-associated renal tumour and sporadic chromophobe renal cell carcinoma.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome, caused by germline alteration of folliculin (FLCN) gene, develops hybrid oncocytic/chromophobe tumour (HOCT) and chromophobe renal cell carcinoma (ChRCC), whereas sporadic ChRCC does not harbor FLCN alteration. To date, molecular characteristics of these similar histological types of tumours have been incompletely elucidated. METHODS: To elucidate renal tumourigenesis of BHD-associated renal tumours and sporadic renal tumours, we conducted whole genome sequencing (WGS) and RNA-sequencing (RNA-seq) of sixteen BHD-associated renal tumours from nine unrelated BHD patients, twenty-one sporadic ChRCCs and seven sporadic oncocytomas. We then compared somatic mutation profiles with FLCN variants and RNA expression profiles between BHD-associated renal tumours and sporadic renal tumours. FINDINGS: RNA-seq analysis revealed that BHD-associated renal tumours and sporadic renal tumours have totally different expression profiles. Sporadic ChRCCs were clustered into two distinct clusters characterized by L1CAM and FOXI1 expressions, molecular markers for renal tubule subclasses. Increased mitochondrial DNA (mtDNA) copy number with fewer variants was observed in BHD-associated renal tumours compared to sporadic ChRCCs. Cell-of-origin analysis using WGS data demonstrated that BHD-associated renal tumours and sporadic ChRCCs may arise from different cells of origin and second hit FLCN alterations may occur in early third decade of life in BHD patients. INTERPRETATION: These data further our understanding of renal tumourigenesis of these two different types of renal tumours with similar histology. FUNDING: This study was supported by JSPS KAKENHI Grants, RIKEN internal grant, and the Intramural Research Program of the National Institutes of Health (NIH), National Cancer Institute (NCI), Center for Cancer Research.

Radiofrequency ablation for renal tumours: A retrospective study from a tertiary centre.

Objective: This study aimed to evaluate the safety and efficacy outcomes of percutaneous radiofrequency ablation (RFA) for localised renal cell carcinoma (RCC) in a tertiary hospital patient who remained unfit for surgical intervention. Methods: We retrospectively analysed survival outcomes for patients with biopsy proven RCC treated by RFA at Royal Perth Hospital between September 2009 and May 2018. Complication data were gathered for all patients that underwent renal RFA along with 2- and 5-year recurrence-free survival (RFS) rate and compared the outcomes with data from previous studies. Results: A total of 69 patients (73 procedures) were eligible for the study, and those patients had biopsy-proven RCC with a minimum of 2-year follow-up. The complication rate was 8.2% (6/73) and local recurrence rate 9.6% (7/73). Two-year RFS is 95.7% and 5-year RFS is 78.8% on a median 3.82-year follow-up (interquartile range 1.90-5.75 years). Conclusion: RFA performed at our centre was found to be safe and effective with low complication rates and durable RFS in line with expectations from existing research. Our study demonstrated that RFA is an alternative modality of treatment for small renal tumours in patients unfit for surgical approach.

Congenital mesoblastic nephroma: review of current management and outcomes in a single centre.

BACKGROUND: Congenital mesoblastic nephroma (CMN) is a rare tumour of the kidney with an overall excellent prognosis. Once considered a benign tumour, it is now recognized to carry a risk of recurrence and metastases with subsequent poor outcomes. The potential for genetic aberrations such as ETV6-NTRK3 fusion raises the potential for targeted treatments in certain patients. The optimum mode and frequency of surveillance is unclear. This study aims to assess this institution's experience with CMN and long-term outcomes. METHODS: A single centre retrospective review was performed of all confirmed cases of CMN between October 2001 and January 2021. RESULTS: Nine cases of CMN in patients under 12 months of age were identified. The histopathology, management and outcomes of these patients are discussed. CONCLUSION: CMN overall has a very good prognosis, but a subgroup does exist that will have poor outcomes. It is difficult to accurately identify this group to target adjuvant therapy.

Ruptured Renal Angiomyolipoma.

Teaching Point: This case highlights the importance of extending the medical analysis to other areas with lumbar computed tomography, especially to the kidneys and the retroperitoneum.

LOT and HOT or not. The proliferation of clinically insignificant and poorly characterised types of renal neoplasia.

The classification of malignant tumours is influenced by both immunohistochemical and molecular genetic findings. This is highlighted in the latest World Health Organization classification of renal neoplasia, which has a tumour category of 'tumours that are molecularly defined'. This implies that the defining molecular features are integral to tumourigenesis, which may not necessarily be the case. Renal oncocytoma is recognised as a benign tumour with variable morphology and immunoexpression. A variant of these tumours is hybrid oncocytic chromophobe tumour, which has features of both oncocytoma and chromophobe renal cell carcinoma and may, on rare occasions, show malignant behaviour. Recent reports have proposed two further entities with eosinophilic cytoplasm and varying nuclear pleomorphism, designated low grade oncocytic tumour (LOT) and eosinophilic vacuolated tumour (EVT), formally known as high grade oncocytic tumour (HOT). The diagnosis of these apparently benign tumours was made on the basis of morphological and immunohistochemical features. More recently it has been claimed that the mutations in the mTOR pathway are also a diagnostic feature and it is further suggested that these mutations are key to the pathogenesis of these tumours. As is seen in oncocytoma, immunohistochemical expression of tumours included in series of LOT and EVT is variable. The mutations in the mTOR pathway, where detected, were not constant, with any combination of mTOR, TSC1 and/or TSC2 being involved. A major issue is that in many of the studies full comparative genomic hybridisation results are not presented. In addition it is well recognised that mTOR mutations are seen in a variety of renal tumours. In view of these conflicting results, the rarity of these tumours and their apparent benign nature, raises questions as to why these tumours should be considered specific entities.

Comparison of perinephric fat measurements between malignant and benign renal tumours.

OBJECTIVE: To investigate different parameters derived from the quantity and quality of perinephric fat, and to compare their effectiveness in predicting the malignant pathology of renal tumours. METHODS: Data from patients diagnosed with renal tumour between April 2014 and December 2020 were retrospectively reviewed, and patients were categorized into malignant or benign tumour groups. Fat parameters, including perinephric fat volume (PFV), perinephric fat area (PFA), perinephric fat thickness (PFT), and Mayo adhesive probability (MAP) score were measured using abdominal computed tomography scans. Between-group differences were assessed by analysis of variance and χ2-test. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the performance of perinephric fat parameters in diagnosing malignancy. RESULTS: A total of 109 patients were included. MAP score, PFV, PFA, and PFT were significantly increased in the malignant versus benign tumour group, and after correction for body mass index (BMI), the indexed PFV/BMI, PFA/BMI, and PFT/BMI values remained significantly higher in the malignant tumour group. All parameters showed fair predictivity of malignancy, with comparable area under the curve values in the ROC curve. CONCLUSION: An increased amount of perinephric fat is predictive of malignant pathology for renal tumours. The predictive accuracy for each perinephric fat parameter remained fair after correcting for BMI.

A systematic review and meta-analysis on the management of concomitant abdominal aortic aneurysms and renal tumours.

OBJECTIVES: The treatment of concomitant abdominal aortic aneurysms and renal tumours is controversial. The aim of this study was to ascertain which of the following three strategies, one-stage open aneurysm repair and nephrectomy, two-stage open aneurysm repair and nephrectomy or two-stage endovascular aneurysm repair and nephrectomy, is the best approach. METHODS: systematic review and meta-analysis of articles published between January 1992 and April 2021 describing the treatment of concomitant abdominal aortic aneurysms and renal tumours. RESULTS: A total of 1168 records were identified. After the selection process, 12 studies with data on 89 patients were included. Sixty-two patients underwent one-stage open procedures, 18 patients underwent two-stage open procedures and nine underwent two-stage endovascular procedures. The overall postoperative mortality was 0.82% (95% CI, 0.00-4.61). The postoperative mortality for one-stage open procedures was 3.09% (95% CI, 0.00-10.11). No deaths occurred in the postoperative period open two-stage procedures or two-stage endovascular procedures. The weighted postoperative morbidity for all procedures was 23.86% (95% CI, 12.64-35.08) and for open one-stage procedures was 37.40% (95% CI, 14.33-60.47). Data concerning postoperative complications of two-stage open procedures were extractable from only one patient in whom no complications were reported. Two postoperative complications were reported after two-stage endovascular procedures from a total of six patients with extractable postoperative data. We were unable to perform meta-analysis on long-term outcomes as the data were reported non-uniformly. CONCLUSION: There is currently no evidence to suggest that any procedure is associated with better outcomes. However, a one-stage open approach was the most commonly used option, favoured as it avoids delaying treatment of either of the conditions. Two-stage open procedures were preferred in cases where the surgical risk of a one-stage procedure was higher than the potential benefit. For such cases, two-stage endovascular repair is becoming more popular as a less invasive approach.

Is off-clamp robot-assisted partial nephrectomy beneficial for renal function? Data from the CLOCK trial.

OBJECTIVES: To compare the functional outcomes of on- vs off-clamp robot-assisted partial nephrectomy (RAPN) within a randomized controlled trial (RCT). MATERIALS AND METHODS: The CLOCK study (CLamp vs Off Clamp the Kidney during robotic partial nephrectomy; NCT02287987) is a multicentre RCT including patients with normal baseline function, two kidneys and masses with RENAL scores ≤ 10. Pre- and postoperative renal scintigraphy was prescribed. Renal defatting and hilum isolation were required in both study arms; in the on-clamp arm, ischaemia was imposed until the completion of medullary renorraphy, while in the off-clamp condition it was not allowed throughout the procedure. The primary endpoint was 6-month absolute variation in estimated glomerular filtration rate (AV-GFR); secondary endpoints were: 12, 18 and 24-month AV-GFR; 6-month estimated glomerular filtration rate variation >25% rate (RV-GFR >25); and absolute variation in ipsilateral split renal function (AV-SRF). The planned sample size was 102 + 102 cases, after taking account crossover of cases to the alternate study arm; a 1:1 randomization was performed. AV-GFR and AV-SRF were compared using analysis of covariation, and RV-GFR >25 was assessed using multivariable logistic regression. Intention-to-treat (ITT) and per-protocol analyses (PP) were performed. RESULTS: A total of 160 and 164 patients were randomly assigned to on- and off-clamp RAPN, respectively; crossover was observed in 14% and 43% of the on- and off-clamp arms, respectively. We were unable to find any statistically significant difference between on- vs off-clamp with regard to the primary endpoint (ITT: 6-month AV-GFR -6.2 vs -5.1 mL/min, mean difference 0.2 mL/min, 95% confidence interval [CI] -3.1 to 3.4 [P = 0.8]; PP: 6-month AV-GFR -6.8 vs -4.2 mL/min, mean difference 1.6 mL/min, 95% CI -2.3 to 5.5 [P = 0.7]) or with regard to the secondary endpoints. The median warm ischaemia time was 14 vs 15 min in the ITT analysis and 14 vs 0 min in the PP analysis. CONCLUSION: In patients with regular baseline function and two kidneys, we found no evidence of differences in functional outcomes for on- vs off-clamp RAPN.

Metastatic atypical renal tumour with metanephric characteristics treated with Sunitinib.

Metanephric Adenoma (MA) is a rare and unclassifiable renal tumour with sparse reported clinical and morphological features. Generally MA's have a benign course without recurrence after nephrectomy, however a few cases received oncological treatment due to malignant progression. We present a 42-year-old woman who years after an initial nephrectomy developed several processes and biopsy confirmed recurrence of MA. Sunitinib was given for only two weeks, as she developed side-effects and currently the patient undergoes control scans with only minimal growth of the processes. This is the first case of MA treated with Tyrosin-Kinase-Inhibitor.

A Rare Case of a Large Primary Renal Neuroendocrine Tumour: A Case Report and Brief Review of Literature.

Primary renal neuroendocrine tumours are very rare clinical entities, and as such, relatively little is known about their clinical progression. Here, we outline the case of a young female patient presenting with abdominal pain and a large 14 cm right renal mass. Initial radiological studies demonstrated localised disease, but during surgical resection, widespread liver metastasis was identified. Histological analysis revealed a grade 2, well-differentiated neuroendocrine tumour pT3a. Whilst surgical resection remains the gold standard for localised disease, further work is required to understand the pathogenesis, prognostic indicators and treatment following metastatic spread. The poor prognosis seen in primary renal neuroendocrine neoplasia highlights the importance of further directed research in this area.

Patients' radiation dose in computed tomography-fluoroscopy-guided percutaneous cryoablation for small renal tumors.

PURPOSE: This study aimed to evaluate patients' radiation dose in computed tomography (CT)-fluoroscopy-guided cryoablation for small renal tumors and assess the possible factors affecting it. METHODS: In our institution, cryoablation was performed in 152 patients between 2013 and 2020. Procedures that were not for renal tumors and did not have radiation dose records and detailed information were excluded from the analysis. The size-specific dose estimates (SSDE), volume CT dose index (CTDIvol), dose-length product (DLP), and entrance skin dose (ESD) were evaluated for both spiral scan and CT-fluoroscopy. The effects of the number of cryoneedle punctures; combined use of hydro- and/or pneumodissection procedures; patients' characteristics, such as body-mass index (BMI); and the tumor-related factors, such as tumor location, were determined by the univariate and multivariate analyses. RESULTS: In the 72 included procedures, the median SSDE was 658 mGy and the median CTDIvol was 456 mGy. The median percentage dose of CT-fluoroscopy to the total procedure dose was estimated as 89.8% (591/658 mGy) with SSDE and 41.4% (611/1,475 mGy cm) with DLP. The combined use of hydro- and/or pneumodissection and number of cryoneedle punctures were significantly associated with the total ESD, and the maximum total ESD was 863 mGy in our cases. CONCLUSIONS: Using SSDE as an index, 89.8% of patients' radiation dose was attributed to CT-fluoroscopy, and ESD for the total procedure did not exceed 1 Gy. The increased number of cryoneedle punctures and combined use of hydro- and/or pneumodissection increased the total ESD.