Renal synovial sarcoma: Considerations for radical nephrectomy- a case report and literature review.

Synovial sarcoma, a rare soft tissue malignancy typically arising from synovial tissue, primarily manifests in the extremities but it may uncommonly present in other locations such as kidneys. Primary renal synovial sarcoma is an uncommon sarcoma with high mortality and recurrence rates. Here, we present a teenage boy with primary renal synovial sarcoma who was referred to our institution.

Are Renal Tumor Diagnostics Becoming Too Advanced for Many Pathology Laboratories?

The recent influx of novel renal neoplasms, particularly molecularly-defined renal carcinomas, has introduced new challenges in the daily practice of most pathology laboratories. These tumors are uncommon, they do not always have well-established morphologic features, and the expression profile of most common biomarkers is not well understood. Moreover, the diagnosis of molecularly-defined renal carcinomas requires the documentation of the disease-defining molecular alteration, with molecular studies or surrogate immunohistochemical markers. Unfortunately, most pathology laboratories lack molecular laboratories, or it is not cost-effective to maintain assays of the specific biomarkers in these unusual tumors. Pathologists should have updated knowledge about the recent changes in renal neoplasms and be aware of these limitations.

Time course of complications after small renal mass biopsy: evaluation of initial follow-up images.

PURPOSE: To retrospectively assess the time course of complications after image-guided small renal mass biopsy using initial follow-up imaging. MATERIALS AND METHODS: A total of 190 masses (mean, 2.1 ± 0.70 cm; range, 0.6-3.8 cm) were assessed using initial computed tomography (43 non-enhanced and 141 enhanced) or magnetic resonance imaging (five non-enhanced and one enhanced) after biopsy. Initial follow-up imaging was classified into two groups (i.e., with or without hematoma) and various factors were compared. RESULTS: The masses were histologically diagnosed in all patients except one. Post-procedural complications included 129 Grade I hematomas, 1 Grade I hemothorax, 9 Grade II hematomas, and 1 Grade IIIa pneumothorax. Residual 28 Grade I and 6 Grade II hematomas and 8 new complications (6 small hematomas, 1 pseudoaneurysm, and 1 arteriovenous fistula) were observed on the initial follow-up imaging obtained at a median of 21 days (3-90 days) after the biopsy. On the initial follow-up imaging, the groups with and without hematoma differed significantly in the following factors: age (P = 0.04), size (P = 0.02), guided images (P < 0.01), hematoma at the end of the procedure (P < 0.01), and days after biopsy (P < 0.01). Although three masses exhibited > 25% shrinkage, no significant change was observed in mass diameter on initial follow-up imaging (mean, 2.1 ± 0.71 cm; P = 0.90). CONCLUSION: Initial follow-up imaging after a biopsy revealed improvements in most of the complications, a few new complications, and an unchanged mass diameter.

[Long-term survival analysis of 1 367 patients treated with radical nephrectomy from a single center].

Objective: To report the long-term survival of renal cell carcinoma (RCC) patients treated with radical nephrectomy in Sun Yat-sen University Cancer Center. Methods: We retrospectively analyzed the clinical, pathological and follow-up records of 1 367 non-metastatic RCC patients treated with radical nephrectomy from 1999 to 2020 in this center. The primary endpoint of this study was overall survival rate. Survival curves were estimated using the Kaplan-Meier method, and group differences were compared through Log-rank test. Univariate and multivariate Cox analysis were fit to determine the clinical and pathological features associated with overall survival rate. Results: A total of 1 367 patients treated with radical nephrectomy with complete follow-up data were included in the study. The median follow-up time was 52.6 months, and 1 100 patients survived and 267 died, with the median time to overall survival not yet reached. The 5-year and 10-year overall survival rates were 82.8% and 74.9%, respectively. The 5-year and 10-year overall survival rates of Leibovich low-risk patients were 93.3% and 88.2%, respectively; of Leibovich intermediate-risk patients were 82.2% and 72.3%, respectively; and of Leibovich high-risk patients were 50.5% and 30.2%, respectively. There were significant differences in the long-term survival among the three groups (P<0.001). The 10-year overall survival rates for patients with pT1, pT2, pT3 and pT4 RCC were 83.2%, 73.6%, 55.0% and 31.4%, respectively. There were significant differences among pT1, pT2, pT3 and pT4 patients(P<0.001). The 5-year and 10-year overall survival rates of patients with lymph node metastasis were 48.5% and 35.6%, respectively, and those of patients without lymph node metastasis were 85.1% and 77.5%, respectively. There was significant difference in the long-term survival between patients with lymph node metastasis and without lymph node metastasis. The 10-year overall survival rate was 96.2% for nuclear Grade 1, 81.6% for nuclear Grade 2, 60.5% for nuclear Grade 3, and 43.4% for nuclear Grade 4 patients. The difference was statistically significant. There was no significant difference in the long-term survival between patients with localized renal cancer (pT1-2N0M0) who underwent open surgery and minimally invasive surgery (10-year overall survival rate 80.5% vs 85.6%, P=0.160). Multivariate Cox analysis showed that age≥55 years (HR=2.11, 95% CI: 1.50-2.96, P<0.001), T stage(T3+ T4 vs T1a: HR=2.37, 95% CI: 1.26-4.46, P=0.008), local lymph node metastasis (HR=3.04, 95%CI: 1.81-5.09, P<0.001), nuclear grade (G3-G4 vs G1: HR=4.21, 95%CI: 1.51-11.75, P=0.006), tumor necrosis (HR=1.66, 95% CI: 1.17-2.37, P=0.005), sarcomatoid differentiation (HR=2.39, 95% CI: 1.31-4.35, P=0.005) and BMI≥24kg/m(2) (HR=0.56, 95%CI: 0.39-0.80, P=0.001) were independent factors affecting long-term survival after radical nephrectomy. Conclusions: The long-term survival of radical nephrectomy in patients with renal cell carcinoma is satisfactory. Advanced age, higher pathological stage and grade, tumor necrosis and sarcomatoid differentiation were the main adverse factors affecting the prognosis of patients. Higher body mass index was a protective factor for the prognosis of patients.

Malignant Perivascular Epithelioid Cell Neoplasm of Left Kidney Treated With Targeted Therapy: A Rare Case Report.

Perivascular epithelioid cell neoplasm (PEComa) is one of the rare entities which is challenging to diagnose clinically. These tumors occur due to tuberous sclerosis complex gene mutations leading to upregulation and overexpression of the mammalian target of rapamycin (mTOR). Malignant PEComas are rare, and we report a peculiar case of PEComa treated with mTOR inhibitors. A 43-year-old woman presented with complaints of back pain, intermittent fever, dysuria, and cough with expectoration for one month. Abdominal computed tomography (CT) revealed heterogeneously enhancing exophytic mass of the left kidney. A positron emission tomography CT whole body showed a primary malignancy in the left kidney, sclerotic lesions in the bony skeleton, and lymphangitis carcinomatosis in both lungs. A biopsy of the left renal mass revealed PEComa, focally positive for melanocytic and muscle markers. She was commenced on treatment with intravenous temsirolimus, and there was a complete tumor regression by the end of the completion of six cycles.

Decoding the Possible Molecular Mechanisms in Pediatric Wilms Tumor and Rhabdoid Tumor of the Kidney through Machine Learning Approaches.

Objective: Wilms tumor (WT) and Rhabdoid tumor (RT) are pediatric renal tumors and their differentiation is based on histopathological and molecular analysis. The present study aimed to introduce the panels of mRNAs and microRNAs involved in the pathogenesis of these cancers using deep learning algorithms. Methods: Filter, graph, and association rule mining algorithms were applied to the mRNAs/microRNAs data. Results: Candidate miRNAs and mRNAs with high accuracy (AUC: 97%/93% and 94%/97%, respectively) could differentiate the WT and RT classes in training and test data. Let-7a-2 and C19orf24 were identified in the WT, while miR-199b and RP1-3E10.2 were detected in the RT by analysis of Association Rule Mining. Conclusion: The application of the machine learning methods could identify mRNA/miRNA patterns to discriminate WT from RT. The identified miRNAs/mRNAs panels could offer novel insights into the underlying molecular mechanisms that are responsible for the initiation and development of these cancers. They may provide further insight into the pathogenesis, prognosis, diagnosis, and molecular-targeted therapy in pediatric renal tumors.

[Establishment and validation of a novel nomogram to predict overall survival after radical nephrectomy].

Objective: To establish a nomogram prognostic model for predicting the 5-, 10-, and 15-year overall survival (OS) of non-metastatic renal cell carcinoma patients managed with radical nephrectomy (RN), compare the modelled results with the results of pure pathologic staging, the Karakiewicz nomogram and the Mayo Clinic Stage, Size, Grade, and Necrosis (SSIGN) score commonly used in foreign countries, and stratify the patients into different prognostic risk subgroups. Methods: A total of 1 246 non-metastatic renal cell carcinoma patients managed with RN in Sun Yat-sen University Cancer Center (SYSUCC) from 1999 to 2020 were retrospectively analyzed. Multivariate Cox regression analysis was used to screen the variables that influence the prognosis for nomogram establishment, and the bootstrap random sampling was used for internal validation. The time-receiver operating characteristic curve (ROC), the calibration curve and the clinical decision curve analysis (DCA) were applied to evaluate the nomogram. The prediction efficacy of the nomogram and that of the pure pathologic staging, the Karakiewicz nomogram and the SSIGN score was compared through the area under the curve (AUC). Finally, patients were stratified into different risk subgroups according to our nomogram scores. Results: A total of 1 246 patients managed with RN were enrolled in this study. Multivariate Cox regression analysis showed that age, smoking history, pathological nuclear grade, sarcomatoid differentiation, tumor necrosis and pathological T and N stages were independent prognostic factors for RN patients (all P<0.05). A nomogram model named SYSUCC based on these factors was built to predict the 5-, 10-, and 15-year survival rate of the participating patients. In the bootstrap random sampling with 1 000 iterations, all these factors occurred for more than 800 times as independent predictors. The Harrell's concordance index (C-index) of SYSUCC was higher compared with pure pathological staging [0.770 (95% CI: 0.716-0.823) vs 0.674 (95% CI: 0.621-0.728)]. The calibration curve showed that the survival rate as predicted by the SYSUCC model simulated the actual rate, while the clinical DCA showed that the SYSUCC nomogram has a benefit in certain probability ranges. In the ROC analysis that included 857 patients with detailed pathological nuclear stages, the nomogram had a larger AUC (5-/10-year AUC: 0.823/0.804) and better discriminating ability than pure pathological staging (5-/10-year AUC: 0.701/0.658), Karakiewicz nomogram (5-/10-year AUC: 0.772/0.734) and SSIGN score (5-/10-year AUC: 0.792/0.750) in predicting the 5-/10-year OS of RN patients (all P<0.05). In addition, the AUC of the SYSUCC nomogram for predicting the 15-year OS (0.820) was larger than that of the SSIGN score (0.709), and there was no statistical difference (P<0.05) between the SYSUCC nomogram, pure pathological staging (0.773) and the Karakiewicz nomogram (0.826). The calibration curve was close to the standard curve, which indicated that the model has good predictive performance. Finally, patients were stratified into low-, intermediate-, and high-risk subgroups (738, 379 and 129, respectively) according to the SYSUCC nomogram scores, among whom patients in intermediate- and high-risk subgroups had a worse OS than patients in the low-risk subgroup (intermediate-risk group vs. low-risk group: HR=4.33, 95% CI: 3.22-5.81, P<0.001; high-risk group vs low-risk group: HR=11.95, 95% CI: 8.29-17.24, P<0.001), and the high-risk subgroup had a worse OS than the intermediate-risk group (HR=2.63, 95% CI: 1.88-3.68, P<0.001). Conclusions: Age, smoking history, pathological nuclear grade, sarcomatoid differentiation, tumor necrosis and pathological stage were independent prognostic factors for non-metastasis renal cell carcinoma patients after RN. The SYSUCC nomogram based on these independent prognostic factors can better predict the 5-, 10-, and 15-year OS than pure pathological staging, the Karakiewicz nomogram and the SSIGN score of patients after RN. In addition, the SYSUCC nomogram has good discrimination, agreement, risk stratification and clinical application potential.

[Efficacy and safety evaluation of immunotherapy combined with targeted therapy as second-line treatment in patients with metastatic non-clear cell renal cell carcinoma].

Objective: This study aimed to evaluate the efficacy and safety of programmed death-1 (PD-1) inhibitor combined tyrosine kinase inhibitor (TKI) therapy versus TKI monotherapy as the second-line regimen for patients with metastatic non-clear cell renal carcinoma (nccRCC) who failed first-line TKI therapy. Methods: The clinicopathological data of 67 patients with metastatic nccRCC who failed first-line TKI therapy between October 2011 and September 2020 were retrospectively analyzed, including 22 patients who received TKI monotherapy and 45 patients who received TKI plus PD-1 inhibitor as the second-line therapy. The efficacy was assessed according to Response Evaluation Criteria in Solid Tumors version 1.0/1.1 (RECIST 1.0/1.1), the Kaplan-Meier method was used to plot the survival curves, and the Log rank test was used to analyze the differences in the survival between the two groups. Treatment-related adverse events (AEs) after treatment were observed in both groups. Results: The overall objective response rate (ORR) and disease control rate (DCR) were 37.3% (25/67) and 56.7% (38/67), respectively. The overall second-line progression-free survival (PFS) was 7.7 months and Overall Survival (OS) was 25.2 months. The ORR and DCR of patients in the combination therapy group were 48.9% (22/45) and 71.1% (32/45), respectively, which were significantly improved compared with the TKI monotherapy group [13.6% (3/22) and 27.3% (6/22), respectively] (P=0.007 and P=0.001, respectively). The median PFS of 9.2 months for second-line treatment was longer in patients in the combination therapy group than in the TKI monotherapy group (5.2 months, P=0.001), but the median OS was not statistically different between the two groups (28.2 months vs 20.8 months, P=0.068). Common treatment-related AEs included hypertension, diarrhea, fatigue, stomatitis, hand-foot syndrome, and hypothyroidism. The incidence of hypothyroidism was higher in the combination therapy group [40.0% (18/45)] than in the TKI monotherapy group [22.7% (5/22), P=0.044]; the incidence of other treatment-related AEs between the two groups were not statistically significant (all P>0.05). Conclusion: Immune-targeted combination therapy was more effective than TKI monotherapy alone and was well tolerated in the treatment of metastatic nccRCC patients who failed first-line TKIs.

Utility of cytopathologic diagnosis of adult solid renal lesions: An academic Institution's 10-year experience.

BACKGROUND: Fine needle aspiration (FNA) and/or needle core biopsy (NCB) are increasingly used for managing patients with renal lesions, especially small renal masses (SRMs). One of the treatment options for SMRs is active surveillance. Hence, accurate diagnosis of renal lesions is critical for treatment planning. The aim of this study is to investigate the utility of FNA and/or NCB in the diagnosis of adult renal lesions at our institute. MATERIALS AND METHODS: Laboratory information system was queried over a period of 10 years (2011-2020) to identify cases of FNA and/or NCB with touch preparation (TP) of adult renal masses. Patient demographics, cytopathologic diagnoses, ancillary tests and follow-up surgical resection data were reviewed and correlated. RESULTS: A total 138 cases from 138 patients (male = 80, female = 58) were identified. Sixty-one (44.20%) cases had FNA and NCB, 48 (34.78%) had NCB only and 29 (21.01%) had FNA only. 118 (85.50%) cases had definitive diagnoses and 13 (9.42%) had indeterminant diagnoses and seven cases were non-diagnostic (5.07%). Most common benign and malignant diagnoses were oncocytoma and clear cell renal cell carcinoma (CCRCC). 41/138 (29.71%) cases had follow-up resection. There were no false positive or false negative cases. Subtyping was feasible in majority cases with only 3/138 (2.17%) misclassified cases. CONCLUSIONS: Majority of renal masses (85.50%) had definitive cytology diagnoses. Only three had misclassification. FNA and/or NCB are useful methods in diagnosing and subclassifying adult renal masses and showed high accuracy (91.89%) when compared to surgical resections.

Well­differentiated neuroendocrine tumor of the right kidney: A case report.

Neuroendocrine tumors (NETs) are tumors originating from neuroendocrine cells and peptidergic neurons. Primary renal well-differentiated NETs (WDNETs) are rare and only sporadic cases have been reported worldwide. In November 2021, a 45-year-old female patient was admitted to The Affiliated Hospital of Zunyi Medical University (Zunyi, China) with right-sided lumbago. Abdominal computed tomography revealed a 44×34×70-mm mass in the right kidney. Following a complete examination, a laparoscopic partial nephrectomy of the right kidney was performed under general anesthesia. The postoperative pathology indicated a well-differentiated NET of the right kidney. There was no tumor recurrence or metastasis during the 1-year follow-up period. WDNETs are rare, their clinical and imaging findings are not specific, and their diagnosis depends on immunohistochemical analysis. The degree of malignancy is low and the prognosis is positive. Surgical resection is often the first choice, and long-term follow-up is required.

Radiomics vs radiologist in bladder and renal cancer. Results from a systematic review.

Introduction: Radiomics in uro-oncology is a rapidly evolving science proving to be a novel approach for optimizing the analysis of massive data from medical images to provide auxiliary guidance in clinical issues. This scoping review aimed to identify key aspects wherein radiomics can potentially improve the accuracy of diagnosis, staging, and grading of renal and bladder cancer. Material and methods: A literature search was performed in June 2022 using PubMed, Embase, and Cochrane Central Controlled Register of Trials. Studies were included if radiomics were compared with radiological reports only. Results: Twenty-two papers were included, 4 were pertinent to bladder cancer, and 18 to renal cancer. Radiomics outperforms the visual assessment by radiologists in contrast-enhanced computed tomography (CECT) to predict muscle invasion but are equivalent to CT reporting by radiologists in predicting lymph node metastasis. Magnetic resonance imaging (MRI) radiomics outperforms radiological reporting for lymph node metastasis. Radiomics perform better than radiologists reporting the probability of renal cell carcinoma, improving interreader concordance and performance. Radiomics also helps to determine differences in types of renal pathology and between malignant lesions from their benign counterparts. Radiomics can be helpful to establish a model for differentiating low-grade from high-grade clear cell renal cancer with high accuracy just from contrast-enhanced CT scans. Conclusions: Our review shows that radiomic models outperform individual reports by radiologists by their ability to incorporate many more complex radiological features.

Preliminary Experience of Partial Nephrectomy Through a New Single-Port Surgical Robot System.

Purpose: To explore the preliminary safety and efficacy of the Shurui single-port (SP) surgical robot in partial nephrectomy (PN). Methods: This study prospectively enrolled patients with T1a renal tumors who met the inclusion criteria from February to July 2022 in The First Affiliated Hospital School of Medicine Zhejiang University. The operative outcomes and perioperative data, including clinical and histological data, were prospectively collected and analyzed. Results: A total of 13 patients were included in this study, including 7 males and 6 females. The median age was 53 (33-74) years, and the average body mass index was 24.9 ± 4.2 kg/m2. There were 6 cases of left kidney tumors and 7 cases of right kidney tumors in the 13 patients. The average tumor diameter was 1.9 ± 0.9 cm. In all operations, the diseased tissue was removed according to the established surgical plan. The average warm ischemia time was 26.2 ± 9.7 minutes; the average device docking time was 3.6 ± 1.8 minutes; and the average robotic arm operation time was 124.7 ± 40.4 minutes. All operations were successfully completed; there was no conversion to open surgery during the operation; and no operation holes were added. The National Aeronautics and Space Administration Task Load Index (NASA-TLX) score was 26.3 ± 2.6 points, and no device-related adverse events occurred during the operation. The median time to discharge was 6 days (range, 4-11 days). Postoperative pathological examination showed that all tumor margins were negative. There were no Clavien grade ≥3 surgical complications in any of the patients during the perioperative period or at the 1-month postoperative follow-up. Conclusion: The new SP surgical robot system is safe, effective, flexible, and stable for application in PN.

Nefrectomía parcial laparoscópica de riñón único "Renal 12xh", presentación de caso y revisión de literatura

La nefrectomia parcial ha proporcionado múltiples beneficios principalmente en pacientes con lesiones renales de pequeño tamaño o con enfermedades que puedan afectar el funcionamiento renal a largo plazo, también en pacientes con riñón único funcional, ya sea congènita o por cirugía, enfermedad renal terminal, tumores renales bilaterales o con enfermedades cromosómicas que afecten la función renal.Se presenta el caso de un paciente de 52 años con un tumor de riñón derecho de 10 cm de diámetro en región interpolar, con riñón izquierdo sin función, por proceso obstructivo de estenosis ureteropielica congènita. Se realizó nefrectomia parcial derecha a pesar de la localización y tamaño del tumor renal, obteniendo excelentes resultados oncológicos y funcionales. Con un seguimiento a doce meses de evaluación post-operatoria sin datos de actividad tumoral, presentando una función renal con creatinina 1.6 mg/dl, con evolución satisfactoria. Conclusiones: La nefrectomia parcial es el manejo ideal para tumores renales pequeños que están localizados en la corteza renal y en los extremos polares del riñón o con un riñón contralateral sin función; pero hay el dilema cuando se presentan en pacientes con función renal baja o tumores localizados cerca del hilio renal de más de 5 cm de diámetro, se debe tomar los riesgo de intentar realizar este procedimiento, el abordaje por via laparoscópica es excelente opción con excelentes resultados, con menor riesgo de complicaciones, y menor sangrado que cirugía abierta.

Nephron-sparing surgery (partial nephrectomy) has provided multiple benefits, mainly in patients with small kidney lesions or concomitant diseases that affect overall kidney function in long term, also in patients with a single functional kidney, either congenital or by surgery, end-stage renal disease, bilateral renal tumors or with chromosomal diseases that affects the renal function. The case of a 52-years-old male patient is presented with a 10-cm right kidney tumor in the interpolar region, with not functional left kidney exclusion due to an obstructive process by congenital ureteropyelic stenosis. Right nephron-sparing nephrectomy was performed despite the location and size of the tumor, obtaining excellent oncological and functional results. Follow-up at twelve months of postoperative evolution showed no data of tumor activity, presenting renal function with creatinine of 1.6 mg/dl, with satisfactory evolution. Conclusions: Partial nephrectomy is the standard management for small-volume renal tumors located in the renal cortex and polar areas, or not functional contralateral kidney; but there is the dilemma, when patients appear with impaired renal function or tumors located near the renal hilum by > 5 cm of diameter, the risk of performs this procedure must be taken, the laparoscopic approach is an excellent option. with great results, and minor bleeding than open surgery.

Differentiating Oncocytic Renal Tumors from Chromophobe Renal Cell Carcinoma: Comparison of Peak Early-phase Enhancement Ratio to Clinical Risk Factors and Rater Predictions.

Background: Most surgically resected benign renal tumors are found to be oncocytomas or indolent hybrid oncocytic tumors, which are difficult to differentiate from chromophobe renal cell carcinoma (chRCC) on renal mass biopsy. Both often exhibit CD117+ staining. Objective: To evaluate the ability of the peak early-phase enhancement ratio (PEER) to distinguish oncocytomas from chRCC and compare its discrimination to traditional clinical risk factors and blinded clinical raters. Design setting and participants: This was a diagnostic case-control study of patients (2006-2020) with oncocytoma or chRCC according to surgical pathology. Intervention: Partial or radical nephrectomy. Outcome measurements and statistical analysis: Three clinical raters blinded to histology measured the PEER and the presence of stellate scar and predicted the final histology for each tumor. Averaged and individual PEER values were compared to surgical pathology and assessed for interobserver variability. Subanalyses were conducted for patients with confirmed CD117+ status. Results and limitations: For the 76 patients identified, PEER was higher among the 32 (42.1%) oncocytomas than among the 44 (57.9%) chRCCs (median 0.81 vs 0.43; p < 0.001), with high correlation across raters (correlation coefficients ≥0.85). A PEER cutoff of <0.60 was strongly associated with identification of chRCC (OR 95.7 (95% CI 19.9-460.8), p < 0.001). In the overall and CD117+ cohorts, sensitivity was 93.2% and 97.0%, the negative predictive value was 90.3% and 95.5%, and the area under the receiver operating characteristic curve (AUC) on multivariable modeling was 95.0% and 98.1%, respectively. PEER outperformed models with clinical risk factors alone (AUC 70.4%) and histology predictions by three raters (AUC 51.6%, 62.5%, and 63.1%). Limitations include reliance on surgical pathology and inclusion of a mix of early contrast-enhanced phases. Conclusions: PEER reliably differentiated benign renal oncocytomas and indolent hybrid tumors from malignant chRCC with excellent diagnostic performance. A diagnostic pathway with biopsy, CD117 staining, and PEER deserves further study to potentially avoid unnecessary surgery for oncocytic renal tumors. Patient summary: We assessed a measurement called PEER on computed tomography (CT) scans and found higher values for benign and lower values for malignant kidney masses, so we were able to tell these apart. PEER was reliable for identifying tumors with positive staining for the CD117 protein biomarker as well as in the overall patient group. Our results show that PEER could be considered for use with biopsy and CD117 staining to potentially avoid unnecessary surgery for benign kidney masses.

Stratification of malignant renal neoplasms from cystic renal lesions using deep learning and radiomics features based on a stacking ensemble CT machine learning algorithm.

Using nephrographic phase CT images combined with pathology diagnosis, we aim to develop and validate a fusion feature-based stacking ensemble machine learning model to distinguish malignant renal neoplasms from cystic renal lesions (CRLs). This retrospective research includes 166 individuals with CRLs for model training and 47 individuals with CRLs in another institution for model testing. Histopathology results are adopted as diagnosis criterion. Nephrographic phase CT scans are selected to build the fusion feature-based machine learning algorithms. The pretrained 3D-ResNet50 CNN model and radiomics methods are selected to extract deep features and radiomics features, respectively. Fivefold cross-validated least absolute shrinkage and selection operator (LASSO) regression methods are adopted to identify the most discriminative candidate features in the development cohort. Intraclass correlation coefficients and interclass correlation coefficients are employed to evaluate feature's reproducibility. Pearson correlation coefficients for normal distribution features and Spearman's rank correlation coefficients for non-normal distribution features are used to eliminate redundant features. After that, stacking ensemble machine learning models are developed in the training cohort. The area under the receiver operator characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) are adopted in the testing cohort to evaluate the performance of each model. The stacking ensemble machine learning algorithm reached excellent diagnostic performance in the testing dataset. The calibration plot shows good stability when using the stacking ensemble model. Net benefits presented by DCA are higher than the Bosniak 2019 version classification when employing any machine learning algorithm. The fusion feature-based machine learning algorithm accurately distinguishes malignant renal neoplasms from CRLs, which outperformed the Bosniak 2019 version classification, and proves to be more applicable for clinical decision-making.

Renal primitive neuroectodermal tumor. The first case series from Syria.

Primitive neuroectodermal tumor (PNET) mainly arises from soft tissues of the extremities such as humerus, femur, C tibia. It rarely arises from kidney; less than 200 cases have been reported in the literature. The clinical presentation and radiography findings are not specific. Here we first report two cases of renal primitive neuroectodermal tumor in Syria. the first patient was 26-year-old- female that presented to urology clinic complaining of right flank pain. Ultrasonography of the abdomen showed a large mixed heterogeneous mass in the right kidney with no hemorrhage or calcification and MSCT of abdomen and pelvis demonstrate a mixed well-demarcated heterogeneous mass measuring (74*117) mm in the right kidney right radical nephrectomy was performed. The second patient 19-year-old-male presented with left flank pain. Ultrasonography of the abdomen showed mixed large mass involving the left kidney, with unmarked border. The CT of the abdomen and pelvis demonstrating a (30*110*90) mm left renal mass and periaortic lymphadenopathy measuring (45*28) mm. The patient underwent Left radical nephrectomy with periaortic lymphadenectomy dissection. The final diagnosis for both cases was Renal PNET based on microscopic and immunohistochemistry examination. In patient with suspected renal mass in the radiographic images, the diagnosis of renal primitive neuroectodermal tumor should be kept in the mind despite its rarity. The final diagnosis is done by histopathological study in association with immunohistochemical examination.

Renal tumor biopsy in patients with cT1b-T4-M0 disease susceptible to radical nephrectomy: analysis of safety, accuracy and clinical impact on definitive management.

PURPOSE: Renal tumor biopsy was provided in patients candidate to radical nephrectomy for a renal mass ≥4 cm, to evaluate treatment deviation. METHODS: Between 2008 and 2017, 102 patients with a solid renal mass ≥4 cm with no distant metastases underwent preliminary renal tumor biopsy. We investigated the proportion of patients who proceeded with radical nephrectomy, variables predicting non-renal cell carcinoma (RCC) and concordance between biopsy findings and definitive pathology. RESULTS: Median tumor size was 70 mm (IQR 55-110). Clinical stage was cT1b in 41, cT2 in 33, cT3 in 25 and cT4 in three patients. A median of three (IQR 2-3) renal tumor biopsies were taken with 16/18 Gauge needles in 97% of cases. Clavien grade I complications occurred in five cases. Malignant tumors were documented in 84 patients: 78 RCCs and six non-RCCs. Fifteen biopsies documented oncocytoma and three were non-diagnostic. Grade was reported in 50 RCCs: 42 (84%) were low and eight (16%) high grade. Eighty-three patients proceeded with radical nephrectomy; six non-RCC malignant tumors underwent combined and/or intensified treatment; 13 of 15 patients with oncocytoma did not undergo radical nephrectomy (eight underwent observation). Definitive pathology confirmed diagnosis in all cases. Grade concordance was 84%, considering two tiers (high vs low grade). No preoperative clinical variable predicted definitive pathology. CONCLUSIONS: Renal tumor biopsy is a safe procedure that leads to radical nephrectomy in most tumors ≥4 cm. Nonetheless, 20% of patients exhibited non-RCC histology. Renal tumor biopsy should be considered in this setting.

Wilms or non-Wílms tumors? Imaging features of renal tumors in pediatrics / ¿Tumores de Wilms o no Wilms? Características por imagen de los tumores renales en pediatría

Abstract Introduction: Identifying the imaging features of renal tumors in pediatric population allows reaching more accurate diagnoses and implementing more appropriate treatments. Objective: To describe the imaging findings of renal tumors in children and to assess the association between imaging findings and histological diagnosis of Wilms tumors versus Non-Wilms tumors, and between imaging features and intraoperative rupture of Wilms tumors, as well as the level of agreement between radiological and histological diagnosis (Wilms vs. Non-Wilms tumor). Materials and methods: Cross-sectional study conducted in 47 children with a pathological diagnosis of kidney tumor and treated between 2012 and 2018 in a pediatric hospital in Bogotá D.C., Colombia. The patients' medical records, as well as their ultrasound, tomography and magnetic resonance studies were reviewed. Two univariate logistic regression analyses were performed to assess the association between imaging findings and histopathological diagnosis and between imaging features and intraoperative rupture of Wilms tumors, calculating the respective Odds Ratio (OR) with a 95% confidence interval. In addition, the level of agreement between radiological and histological diagnosis was determined using the Cohen's kappa coefficient. Results: A significant association was found between histological diagnosis of Wilms tumor and the presence of necrosis, tumor enhancement, pseudocapsule, rupture signs, tumor volume and tumor size (OR: 21.6, 15.17, 14.57, 8.21, 7.93, and 4.37, respectively; p<0.05). An association between having Wilms tumors and a lower frequency of metastases was also found (OR: 0.19; p<0.05). The kappa coefficient between radiological diagnosis of Wilms/non- Wilms tumors and histological diagnosis was 0.78 (CI95%: 0.59-0.96; p<0.05). Additionally, Wilms tumors volumen was significantly associated with the occurrence of rupture (OR: 3.08; p<0.05). Conclusions: There are imaging findings such as necrosis, tumor enhancement and tumor volume that can help predict the histological diagnosis of Wilms tumors, as well as perioperative rupture. In addition, a moderate to very good concordance between radiological diagnosis of Wilms/non-Wilms tumors and histological findings was found.

Resumen Introducción. Identificar las características por imagen de los tumores renales en la población pediátrica permite realizar diagnósticos más precisos e implementar tratamientos más apropiados. Objetivo. Describir los hallazgos de imagen de tumores renales en niños y evaluar la asociación entre hallazgos imagenológicos y el diagnóstico histopatológico de tumores de Wilms versus tumores no Wilms, y entre las características de imagen y ruptura quirúrgica de tumores Wilms, así como el grado de concordancia entre el diagnóstico radiológico e histológico. Materiales y métodos. Estudio transversal realizado en 47 niños con diagnóstico patológico de tumor renal atendidos entre 2012 y 2018 en un hospital pediátrico de Bogotá D.C., Colombia. Se revisaron las historias clínicas de los pacientes, así como sus estudios de ultrasonografía, tomografía y resonancia magnética. Se realizaron dos análisis de regresión logística univariados para evaluar la asociación entre hallazgos imagenológicos y diagnóstico histopatológico y entre las características imagenológicas de los tumores de Wilms y ruptura quirúrgica, calculando los respectivos odds ratio (OR) con un intervalo de confianza del 95%. Además, se determinó el grado concordancia entre el diagnóstico radiológico e histopatológico mediante el coeficiente de kappa de Cohen. Resultados. Se encontró una asociación significativa entre el diagnóstico histológico de tumor de Wilms y la presencia de necrosis, realce tumoral, pseudocápsula, signos de ruptura, volumen y tamaño del tumor (OR: 21.6, 15.17, 14.57, 8.21, 7.93 y 4.37, respectivamente; p<0.05). También se observó una asociación entre tener tumores de Wilms y menor frecuencia de metástasis (OR:0.19; p<0.05). El coeficiente de Kappa entre el diagnóstico radiológico de los tumores (Wilms/no-Wilms) y el diagnóstico histológico fue 0.78 (IC95%: 0.59-0.96; p<0.05). Además, el volumen de los tumores de Wilms se asoció significativamente con la ocurrencia de ruptura (OR: 3.08; p<0.05). Conclusiones. Hay hallazgos imagenológicos como la necrosis, el realce tumoral y el volumen tumoral que ayudan a predecir el diagnóstico histológico de tumores de Wilms, así como la ruptura perioperatoria. Además, se observó una muy buena concordancia entre el diagnóstico radiológico de tumores Wilms/no Wilms y los hallazgos histológicos.

Small Renal Masses without Gross Fat: What Is the Role of Contrast-Enhanced MDCT?

Increased detection of small renal masses (SRMs) has encouraged research for non-invasive diagnostic tools capable of adequately differentiating malignant vs. benign SRMs and the type of the tumour. Multi-detector computed tomography (MDCT) has been suggested as an alternative to intervention, therefore, it is important to determine both the capabilities and limitations of MDCT for SRM evaluation. In our study, two abdominal radiologists retrospectively blindly assessed MDCT scan images of 98 patients with incidentally detected lipid-poor SRMs that did not present as definitely aggressive lesions on CT. Radiological conclusions were compared to histopathological findings of materials obtained during surgery that were assumed as the gold standard. The probability (odds ratio (OR)) in regression analyses, sensitivity (SE), and specificity (SP) of predetermined SRM characteristics were calculated. Correct differentiation between malignant vs. benign SRMs was detected in 70.4% of cases, with more accurate identification of malignant (73%) in comparison to benign (65.7%) lesions. The radiological conclusions of SRM type matched histopathological findings in 56.1%. Central scarring (OR 10.6, p = 0.001), diameter of lesion (OR 2.4, p = 0.003), and homogeneous accumulation of contrast medium (OR 3.4, p = 0.03) significantly influenced the accuracy of malignant diagnosis. SE and SP of these parameters varied from 20.6% to 91.3% and 22.9% to 74.3%, respectively. In conclusion, MDCT is able to correctly differentiate malignant versus uncharacteristic benign SRMs in more than 2/3 of cases. However, frequency of the correct histopathological SRM type MDCT identification remains low.