Clinicopathologic characteristics and prognostic factors of sarcomatoid renal cell carcinoma

Deep learning-based prediction of tumor aggressiveness in RCC using multiparametric MRI: a pilot study

OBJECTIVE

To investigate the value of multiparametric magnetic resonance imaging (MRI) as a non-invasive method to predict the aggressiveness of renal cell carcinoma (RCC) by developing a convolutional neural network (CNN) model and fusing it with clinical characteristics.

METHODS

Multiparametric abdominal MRI was performed on 47 pathologically confirmed RCC patients between 2019 and 2023. Preoperative MRI was performed on all patients to assess their clinical characteristics. The CNN model was developed and validated to assess the predictive value of b value images, combined b value images, apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI), and their parametric maps for RCC aggressiveness. The least absolute shrinkage and selection operator (LASSO) regression was used to identify clinical features highly correlated with RCC aggressiveness. These clinical features were combined with selected b values to develop a fusion model. All models were evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 47 patients (mean age, 56.17 ± 1.70 years; 37 men, 10 women) were evaluated. LASSO regression identified renal sinus/perirenal fat invasion, tumor stage, and tumor size as the most significant clinical features. The combined b values of b = 0,1000 achieved an area under the curve (AUC) of 0.642 (95% CI: 0.623-0.661), and b = 0,100,1000 achieved an AUC of 0.657 (95% CI: 0.647-0.667). The fusion model combining clinical features with b = 0,1000 yielded the highest performance with an AUC of 0.861 (95% CI: 0.667-0.992), demonstrating superior predictive accuracy compared to the other models.

CONCLUSION

Deep learning using a CNN fusion model, integrating multiple b value images and clinical features, could effectively promote the preoperative prediction of tumor aggressiveness in RCC patients.

Computed Tomographic Characteristics of Feline Renal Cell Carcinoma and Renal Lymphoma: A Comparative Analysis

This retrospective, multicenter study aimed to identify key computed tomography (CT) features that differentiate renal cell carcinoma (RCC) from lymphoma, the two most common feline renal neoplasms. CT images from 25 cats with renal tumors (15 RCC and 10 lymphoma) were evaluated. Of the RCC cases, 10 were diagnosed through histopathology and 5 through FNA. Among the lymphoma cases, two were extranodal lymphoma, including one case of primary renal lymphoma, and eight were gastrointestinal (GI) lymphoma with renal involvement. Qualitative features (tumor distribution, growth pattern, and enhancement characteristics) and quantitative parameters (tumor size and attenuation values) from triphasic or single post-contrast-enhanced CT scans were analyzed and compared. RCC typically presented as unilateral (93.3%) masses with expansile growth (73.3%) and heterogeneous enhancement among contrast-enhancing tumors (100%). Lymphoma more often showed bilateral involvement (60%), infiltrative growth (50%), and homogeneous enhancement (90%) (p < 0.001). Tumor vessel enhancement was observed exclusively in RCC. Compared with lymphoma, RCC demonstrated significantly higher attenuation values in the late nephrographic/early excretory phase. While histopathology remains the gold standard, this study provides a detailed CT analysis of these tumors, specifically within a feline population.

Synchronous colonic metastasis of sarcomatoid chromophobe renal cell carcinoma. Diagnostic challenges and value of CD10 and vimentin immunostains in diagnosis

In chromophobe renal cell carcinoma (CRCC), sarcomatoid and rhabdoid features denote a dismal prognosis, a short time to recurrence, and metastatic disease after nephrectomy. A 58-year-old male presented for management of a septic shock secondary to stercoral peritonitis. Four months before, he underwent a right nephrectomy for a lower polar renal tumor. The final diagnosis concluded to a pT4 CRCC with extensive sarcomatoid and rhabdoid changes. An abdominal CT-scan objectified a heterogeneous colon mass without renal recurrence. Urgently, the patient underwent right hemicolectomy and segment-VI hepatectomy. Histology suggested high-grade sarcoma with undifferentiated tumor proliferation and a lack of well-differentiated epithelial component. Immunohistochemistry (IHC) confirmed the renal origin of the colon metastasis, which consisted solely of the dedifferentiated component of CRCC. Tumors originating from the kidney should be considered in the differential diagnosis of undifferentiated colorectal cancers. An excellent anatomo-clinical correlation and a suitable IHC workup would reveal the appropriate diagnosis.

Diagnostic and prognostic role of 18F-FDG PET/CT for sarcomatoid differentiation in renal cell carcinoma

BACKGROUND

Sarcomatoid differentiation is an invasive dedifferentiated feature of tumor and associated with poor prognosis in renal cell carcinoma (RCC) patients. This study aimed to evaluate the utility of 18F-FDG PET/CT in predicting sarcomatoid differentiation in RCC and its potential prognostic value.

RESULTS

This retrospective study assessed newly diagnosed sarcomatoid differentiation renal cell carcinoma (SDRCC) patients who were staged using 18F-FDG PET/CT. Patients were categorized into high-grade sarcomatoid differentiation RCC (HG-SDRCC), low-grade sarcomatoid differentiation RCC (LG-SDRCC), and non-sarcomatoid differentiation RCC (non-SDRCC). The maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were compared. Overall survival (OS) and disease-free survival (DFS) were analyzed. SUVmax, MTV, TLG, and SUVmean values were significantly higher in SDRCC compared to non-SDRCC (P < 0.05). Additionally, SUVmax, TLG, and SUVmean were significantly higher in HG-SDRCC compared to non-HG-SDRCC (P < 0.05). ROC curves revealed that SUVmax and SUVmean were effective for distinguishing HG-SDRCC from non-HG-SDRCC. The log-rank test identified SUVmax > 11, MTV > 95, TLG > 500, SUVmean > 5.2, invasion of peripheral tissue and/or organs, and metastasis as risk factors for SDRCC patients. Multivariate Cox proportional hazards model analyses indicated that TLG > 500 was a risk factor for poor DFS, while SUVmax > 11 and SUVmean > 5.2 were risk factors for poor OS.

CONCLUSIONS

18F-FDG PET/CT can effectively differentiate HG-SDRCC with more aggressive malignancy. The prognostic model developed in this study demonstrates that metabolic parameters, particularly TLG for DFS and SUVmax/SUVmean for OS, serve as more robust predictors of patient outcomes than the degree of sarcomatoid differentiation.

CT-based radiomics model using stability selection for predicting the World Health Organization/International Society of Urological Pathology grade of clear cell renal cell carcinoma

OBJECTIVES

This study aimed to develop a model to predict World Health Organization/International Society of Urological Pathology (WHO/ISUP) low-grade or high-grade clear cell renal cell carcinoma (ccRCC) using 3D multiphase enhanced CT radiomics features (RFs).

METHODS

CT data of 138 low-grade and 60 high-grade ccRCC cases were included. RFs were extracted from four CT phases: non-contrast phase (NCP), corticomedullary phase, nephrographic phase, and excretory phase (EP). Models were developed using various combinations of RFs and subjected to cross-validation.

RESULTS

There were 107 RFs extracted from each phase of the CT images. The NCP-EP model had the best overall predictive value (AUC = 0.78), but did not significantly differ from that of the NCP model (AUC = 0.76). By considering the predictive ability of the model, the level of radiation exposure, and model simplicity, the overall best model was the Conventional image and clinical features (CICFs)-NCP model (AUC = 0.77; sensitivity 0.75, specificity 0.69, positive predictive value 0.85, negative predictive value 0.54, accuracy 0.73). The second-best model was the NCP model (AUC = 0.76).

CONCLUSIONS

Combining clinical features with unenhanced CT images of the kidneys seems to be optimal for prediction of WHO/ISUP grade of ccRCC. This noninvasive method may assist in guiding more accurate treatment decisions for ccRCC.

ADVANCES IN KNOWLEDGE

This study innovatively employed stability selection for RFs, enhancing model reliability. The CICFs-NCP model's simplicity and efficacy mark a significant advancement, offering a practical tool for clinical decision-making in ccRCC management.

CT features based preoperative predictors of aggressive pathology for clinical T1 solid renal cell carcinoma and the development of nomogram model

BACKGROUND

We aimed to identify preoperative predictors of aggressive pathology for cT1 solid renal cell carcinoma (RCC) by combining clinical features with qualitative and quantitative CT parameters, and developed a nomogram model.

METHODS

We conducted a retrospective study of 776 cT1 solid RCC patients treated with partial nephrectomy (PN) or radical nephrectomy (RN) between 2018 and 2022. All patients underwent four-phase contrast-enhanced CT scans and the CT parameters were obtained by two experienced radiologists using region of interest (ROI). Aggressive pathology was defined as patients with nuclear grade III-IV; upstage to pT3a; type II papillary renal cell carcinoma (pRCC), collecting duct or renal medullary carcinoma, unclassified RCC or sarcomatoid/rhabdoid features. Univariate and multivariate logistic analyses were used to determine significant predictors and develop the nomogram model. To evaluate the accuracy and clinical utility of the nomogram model, we used the receiver operating characteristic (ROC) curve, calibration plot, decision curve analysis (DCA), risk stratification, and subgroup analysis.

RESULTS

Of the 776 cT1 solid RCC patients, 250 (32.2%) had aggressive pathological features. The interclass correlation coefficient (ICC) of CT parameters accessed by two reviewers ranged from 0.758 to 0.982. Logistic regression analyses showed that neutrophil-to-lymphocyte ratio (NLR), distance to the collecting system, CT necrosis, tumor margin irregularity, peritumoral neovascularity, and RER-NP were independent predictive factors associated with aggressive pathology. We built the nomogram model using these significant variables, which had an area under the curve (AUC) of 0.854 in the ROC curve.

CONCLUSIONS

Our research demonstrated that preoperative four-phase contrast-enhanced CT was critical for predicting aggressive pathology in cT1 solid RCC, and the constructed nomogram was useful in guiding patient treatment and postoperative follow-up.

An exploratory study of CT radiomics using differential network feature selection for WHO/ISUP grading and progression-free survival prediction of clear cell renal cell carcinoma

Objectives

To explore the feasibility of predicting the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade and progression-free survival (PFS) of clear cell renal cell cancer (ccRCC) using the radiomics features (RFs) based on the differential network feature selection (FS) method using the maximum-entropy probability model (MEPM).

Methods

175 ccRCC patients were divided into a training set (125) and a test set (50). The non-contrast phase (NCP), cortico-medullary phase, nephrographic phase, excretory phase phases, and all-phase WHO/ISUP grade prediction models were constructed based on a new differential network FS method using the MEPM. The diagnostic performance of the best phase model was compared with the other state-of-the-art machine learning models and the clinical models. The RFs of the best phase model were used for survival analysis and visualized using risk scores and nomograms. The performance of the above models was tested in both cross-validated and independent validation and checked by the Hosmer-Lemeshow test.

Results

The NCP RFs model was the best phase model, with an AUC of 0.89 in the test set, and performed superior to other machine learning models and the clinical models (all p &lt;0.05). Kaplan-Meier survival analysis, univariate and multivariate cox regression results, and risk score analyses showed the NCP RFs could predict PFS well (almost all p &lt; 0.05). The nomogram model incorporated the best two RFs and showed good discrimination, a C-index of 0.71 and 0.69 in the training and test set, and good calibration.

Conclusion

The NCP CT-based RFs selected by differential network FS could predict the WHO/ISUP grade and PFS of RCC.

Treatment and Outcome of Metastatic Renal Cell Carcinoma With Sarcomatoid Differentiation: A Single-Center, Real-World Analysis of Retrospective Data

Background: Sarcomatoid differentiation/histology of renal cell carcinoma (sRCC) in patients with metastatic renal cell carcinoma (mRCC) is still underresearched in current therapy regimes. We aimed to evaluate the impact of sRCC on outcomes in patients with mRCC treated with tyrosine kinase inhibitors (TKIs).

Methods: We collected complete data of 262 consecutive mRCC patients from our institutional database for this retrospective study. All patients were treated with TKIs within a single or multimodal treatment approach. All analyses were adjusted for the presence of sRCC. Descriptive statistics as well as uni- and multivariable outcome metrics, including progression-free (PFS) and overall survival (OS) as endpoints were performed.

Results: Overall, 18 patients had sRCC (6.9%). Patients with sRCC had more often clear-cell histology (p = 0.047), a higher T-stage (p = 0.048), and underwent cytoreductive nephrectomy more frequently (p < 0.001). The most common first-line TKIs were Sunitinib (65.6%), Sorafenib (19.5%), and Pazopanib (10.3%), respectively. At a median follow-up of 32 months, patients with sRCC had significantly reduced PFS (p = 0.02) and OS (p = 0.01) compared to patients without sRCC. In multivariable analyses that adjusted for the effects of standard mRCC predictors, the sarcomatoid feature retained its independent association with inferior PFS (HR: 2.39; p = 0.007) and OS (HR: 2.37; p = 0.001). This association remained statistically significant in subgroup analyses of patients with Sunitinib as first-line therapy (PFS p < 0.001; OS: p < 0.001).

Conclusion: Despite its rare occurrence, our findings confirm sRCC as a powerful predictor for inferior outcomes in mRCC treated with targeted therapies. This suggests a need for more tailored treatment strategies in patients harboring mRCC with sarcomatoid histology to improve oncological outcomes.

Feline sarcomatoid renal cell carcinoma with peritoneal carcinomatosis and effusion

A 9-y-old, castrated male, domestic medium-hair cat diagnosed previously with chronic kidney disease developed anorexia and vomiting. Ultrasonography revealed abdominal effusion and a left renal perihilar mass. Cytologic evaluation of the peritoneal fluid and mass identified atypical epithelioid cells suspected to be of renal epithelial or possible mesothelial origin. Immunohistochemical (IHC) evaluation of a formalin-fixed, paraffin-embedded peritoneal fluid cell block indicated both pancytokeratin and vimentin expression in the atypical epithelioid cell population. With scanning electron microscopic evaluation, similar epithelioid cells lacked the cell-surface microvilli expected of mesothelium, supporting an antemortem diagnosis of probable carcinoma. On postmortem examination, the left kidney was effaced by an infiltrative neoplasm with myriad similar nodules throughout the peritoneum. The neoplasm was composed primarily of polygonal-to-spindle-shaped cells with strong vimentin and weak pancytokeratin cytoplasmic immunolabeling. Further IHC characterization with PAX8, CK18, KIT, napsin A, SMA, desmin, CD18, and claudin 5 was performed. Histologic and IHC findings supported a diagnosis of sarcomatoid renal cell carcinoma with peritoneal carcinomatosis. An in vitro cell culture line of neoplastic cells harvested from the primary tumor was successfully established for future research endeavors.

Computed Tomography Radiomics for Predicting Pathological Grade of Renal Cell Carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is the most common renal cancer and it has the worst prognosis among all renal cancers. However, traditional radiological characteristics on computed tomography (CT) scans of ccRCC have been insufficient to predict the pathological grade of ccRCC before surgery.

Methods

Patients with ccRCC were retrospectively enrolled into this study and were separated into two groups according to the World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading system, i.e., low-grade (Grade I and II) group and high-grade (Grade III and IV) group. Traditional CT radiological characteristics such as tumor size, pre- and post-enhancing CT densities were assessed. In addition, radiomic texture analysis based on the CT imaging of the ccRCC were also performed. A CT-based machine learning method combining the traditional radiological characteristics and radiomic features was used in the predictive modeling for differentiating the low-grade from the high-grade ccRCC. Model performance was evaluated with the receiver operating characteristic curve (ROC) analysis.

Results

A total of 264 patients with pathologically confirmed ccRCC were included in this study. In this cohort, 206 patients had the low-grade tumors and 58 had the high-grade tumors. The model built with traditional radiological characteristics achieved an area under the curve (AUC) of 0.9175 (95% CI: 0.8765–0.9585) and 0.8088 (95% CI: 0.7064–0.9113) in differentiating the low-grade from the high-grade ccRCC for the training cohort and the validation cohort respectively. The model built with the radiomic textural features yielded an AUC value of 0.8170 (95% CI: 0.7353–0.8987) and 0.8017 (95% CI: 0.6878–0.9157) for the training cohort and the validation cohort, respectively. The combined model integrating both the traditional radiological characteristics and the radiomic textural features achieved the highest efficacy, with an AUC of 0.9235 (95% CI: 0.8646–0.9824) and an AUC of 0.9099 (95% CI: 0.8324–0.9873) for the training cohort and validation cohort, respectively.

Conclusion

We developed a machine learning radiomic model achieving a satisfying performance in differentiating the low-grade from the high-grade ccRCC. Our study presented a potentially useful non-invasive imaging-focused method to predict the pathological grade of renal cancers prior to surgery.

Computed tomography features predicting aggressiveness of malignant parenchymal renal tumors suitable for partial nephrectomy

The aim of this study was to identify and standardize computed tomography (CT) features having a potential role in predicting aggressiveness of malignant parenchymal renal tumors suitable for partial nephrectomy (PN). We performed a non-systematic review of the recent literature to evaluate the potential impact of CT variables proposed by the Society of Abdominal Radiology Disease-Focused Panel on Renal Cell Carcinoma in predicting aggressiveness of newly diagnosed malignant parenchymal renal tumors. The analyzed variables were clinical tumor size, tumor growth rate, enhancement characteristics, amount of cystic component, polar and capsular location, tumor margins and distance between tumor and renal sinus. Unfavorable behavior was defined as: 1) renal cell carcinoma (RCC) with stage ≥pT3; 2) nuclear grade 3 or 4; 3) presence of sarcomatoid de-differentiation; or 4) non-clear cell subtypes with unfavorable prognosis (type 2 papillary RCC, collecting duct or renal medullary carcinoma, unclassified RCC). Beyond clinical tumor size, tumor growth rate, enhancement characteristics, amount of cystic component, tumor margins and distance between tumor and renal sinus are highly relevant features predicting an unfavorable behavior. Moreover, several studies supported the role of necrosis as preoperative predictor of tumor aggressiveness. Peritumoral and intratumoral vasculature as well as capsule status are emerging variables that need to be further evaluated. Tumor size, enhancement characteristics, tumor margins and distance to the renal sinus are highly relevant CT features predicting biological aggressiveness of malignant parenchymal renal tumors. Combination of these parameters might be useful to generate tools to predict the unfavorable behavior of renal tumors suitable for PN.

Frequent KRAS mutations in oncocytic papillary renal neoplasm with inverted nuclei

AIMS

Papillary renal neoplasm with reverse polarity (PRNRP) is a newly documented rare tumour type. Its molecular pathological features have thus far been very little studied.

METHODS AND RESULTS

There were 13 PRNRP cases including 3 The Cancer Genome Atlas (TCGA) cases and our 10 cases in this study. The 3 TCGA cases were found by a combined analysis of GATA3 mRNA expression levels and digital slides from the TCGA papillary renal cell carcinoma project. KRAS codon 12 mutations were identified in the three PRNRPs from TCGA. Of our 10 PRNRP cases, the mutations were also discovered using Sanger sequencing in seven (77.8%) of nine cases with available DNA, where KRAS p.G12V (n = 3), p.G12D (n = 2), p.G12R (n = 1) and p.G12C (n = 1) alterations were found. PRNRP shared similar gene expression profiles with renal distal tubules via an interprofile correlation analysis. Gene set enrichment analysis revealed that genes involved in 'KEGG aldosterone regulated sodium reabsorption' or 'hallmark apical surface' were enriched in PRNRP. Moreover, polarised immunostaining patterns for L1CAM and EMA in the distal tubule were maintained in PRNRP.

CONCLUSIONS

These results imply that the tumour potentially originates from the distal tubule, especially from the cortical collecting duct, and probably retains its cell polarity, except for nuclear inversion. We therefore propose that oncocytic papillary renal neoplasm with inverted nuclei (OPRNIN) is a better name for this tumour type. OPRNIN is a kidney site-specific KRAS mutation neoplasm different from conventional papillary renal cell carcinoma.

Infiltrative Renal Masses: Clinical Significance and Fidelity of Documentation

BACKGROUND

The prevalence of infiltrative renal masses (IRMs) and fidelity of documentation of infiltrative features remain unclear.

OBJECTIVE

To investigate the prevalence/significance of IRMs and assess whether infiltrative features were documented preoperatively.

DESIGN, SETTING, AND PARTICIPANTS

A total of 522 patients with renal tumors managed with partial/radical nephrectomy (2012-2014) whose pathology demonstrated locally advanced and/or aggressive histology were analyzed. Preoperative computed tomography/magnetic resonance imaging was retrospectively/independently reviewed by two radiologists. IRMs were required to have a poorly defined interface with parenchyma and nonelliptical shape in one or more distinct/unequivocal areas. Infiltrative features were defined as extensive or focal.

INTERVENTION

Partial/radical nephrectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cancer-specific mortality (CSM) was estimated using cumulative-incidence analysis. Significant and independent predictors of CSM were evaluated using Cox proportional hazard analysis.

RESULTS AND LIMITATIONS

Median tumor size was 6.9cm; renal cell carcinomas (RCCs) predominated (92%). Image review confirmed 133 IRMs (25%), including 103 RCCs; 59 had sarcomatoid or poorly differentiated features. IRMs were larger and more often symptomatic compared than non-IRMs, and disseminated disease was also more common for IRMs (all p<0.001). Overall, 109 IRMs were imaged at our center; 42 were documented as IRMs in preoperative radiology reports, while infiltrative features were not documented in 67 (61%). Only four (6%) of these 67 were documented as infiltrative by the surgical team. Infiltrative features were more often focal in undocumented IRMs. On multivariable analysis, infiltrative features, disseminated disease, and non-RCC histology were independent predictors of CSM (hazard ratio or HR [95% confidence interval {CI}]=1.73 [1.21-2.47], 2.98 [2.10-4.23], and 2.79 [1.86-4.62], respectively). Among IRMs, extensive infiltrative features and disseminated disease were associated with CSM (HR [95% CI]=1.98 [1.27-3.07] and 2.35 [1.52-3.63], respectively), while documentation status failed to show an association. Excluding patients with disseminated disease or residual cancer after surgery, recurrence rates were 62% for IRMs versus 22% for non-IRMs (p<0.001), and there was again no significant difference between documented and undocumented IRMs (p=0.36). Limitations include a retrospective design.

CONCLUSIONS

Twenty-five percent of locally advanced/histologically aggressive renal tumors exhibited infiltrative features, although many were not documented as IRMs. Among this high-risk surgical population, infiltrative features were independent predictors of CSM, irrespective of whether they were documented or not. Our data suggest that infiltrative features should be assessed and documented routinely during evaluation of renal masses.

PATIENT SUMMARY

Infiltrative renal masses may be more common than previously appreciated, although many were not documented as infiltrative during preoperative evaluation. Our data suggest that infiltrative features have a strong impact on prognosis and should be assessed and documented routinely during radiologic and clinical evaluation of renal masses.

Sarcomatoid Renal Cell Carcinoma: Population-Based Study of 879 Patients

BACKGROUND

Sarcomatoid renal cell carcinoma (sRCC) constitutes a rare and aggressive subtype of renal cell carcinoma. We aimed to investigate its clinicopathologic characteristics and outcomes at a national level.

PATIENTS AND METHODS

We accessed the National Cancer Institute's Surveillance, Epidemiology, and End Results database (2010-2015) and extracted data on patients with sRCC. We estimated median, 1-, 3-, and 5-year disease-specific survival (DSS) probabilities after generation of Kaplan-Meier curves and used multivariable regression to evaluate variables associated with nephrectomy and DSS.

RESULTS

A total of 879 patients with sRCC were identified; 60.9% patients had stage IV disease at diagnosis, and the median tumor size was 8.3 cm (interquartile range, 5.5-12 cm). The 5-year DSS were 77.7%, 67.8%, 35.4%, and 3.5% for patients with stage I, II, III, and IV disease at diagnosis, respectively; median DSS was 9 months (interquartile range, 4-42 months) for the entire cohort. Older age (hazard ratio [HR] = 1.01; 95% confidence interval [CI], 1.00-1.02), higher tumor stage (stage III vs. I: HR = 3.81; 95% CI, 2.18-6.67; stage IV vs. I: HR = 9.89; 95% CI, 5.80-16.98), and performance of nephrectomy (HR = 0.53; 95% CI, 0.43-0.66) were found to independently affect DSS.

CONCLUSION

In the largest sRCC cohort to date, we found that most patients present with metastatic disease, and the prognosis for this disease remains extremely poor. Nephrectomy should be considered in all patients with acceptable surgical risk, including cytoreductive nephrectomy in carefully selected patients with metastatic disease.

Intrarenal urothelial cancers confused as infiltrative renal masses: Report of 22 cases and literature review

Distinguishing infiltrative renal masses (IRMs) from intrarenal urothelial cancers (IUCs) is critically important, but may be challenging for any radiologist or urologist. The present study aimed to summarize the clinical, imaging and pathological characteristics of IRM, which were postoperatively confirmed as IUC. The analysis was performed using the records of 22 patients who were preoperatively diagnosed with IRM but the results of percutaneous biopsies or postoperative pathological analyses led to diagnoses of urothelial cancers (UCs) from January 2011 to December 2017. The demographic data, computed tomography (CT) imaging features and pathological characteristics were evaluated. The present study also reviewed the literature concerning the IRM and IUC. The mean age of patients was 62 years and 86.4% of them were >55 years. The sex and tumor side distributions were equal. Hematuria and/or flank pain were observed in 86.4% of patients. All patients exhibited endophytic solid renal masses with unclear tumor boundaries on CT images. The kidneys of 81.8% of patients maintained their normal shape while mild alternations were observed in 18.2% of cases. A total of 81.8% of patients maintained the reniform shape and 18.2% exhibited mild contour change. Of all patients, all tumors exhibited less or equal attenuation on unenhanced CT images and they were mildlyimproved on enhanced CT. A total of 6 cases were confirmed by biopsy, when patients underwent laparoscopic nephroureterectomy instead of radical nephrectomy. The remaining 16 patients underwent laparoscopic nephrectomy but the postoperative pathological diagnoses revealed the presence of UCs. All postoperatively confirmed cancers were stages T3 and T4 (62.5 and 37.5%, respectively). UCs should be suspected in middle aged or elderly middle-elderly patients presenting renal masses with endophytic solid unclear tumor boundary on unenhanced and slightly enhanced CT images, accompanied with hematuria and/or flank pain. Preoperative biopsy is preferred for complicated cases.

The prognosis of subsequent surgical treatment in patients with sarcomatoid carcinoma in the liver: A retrospective study

BACKGROUND

Sarcomatoid hepatocellular carcinoma (SHC) is a rare disease with a poor prognosis. Due to the scarcity of patients with this condition, the optimal treatment for SHC has not been established. In this study, we compared the benefits of subsequent treatments for surgical SHC patients.

MATERIALS AND METHODS

Clinical records were retrospectively studied. The SHC patients were divided into two groups according to whether subsequent treatment was performed. The overall survival (OS) rates and disease-free survival (DFS) rates were estimated by the Kaplan-Meier method, and comparisons were made using the log-rank test. Univariate and multivariate analyses were evaluated using the Cox proportional hazards regression model.

RESULTS

The study included 25 patients; 9 (36%) had subsequent treatments following surgery. The median OS of the treatment group and non-treatment group were 8.8 months [95% confidence interval (CI) 8.4-9.1] and 5.4 months [95% CI 4.3-6.5], respectively. OS showed statistical significance between the two groups (log-rank, P = 0.025). Univariate analysis suggested that two factors were poor predictors of OS: without subsequent treatment and with capsule formation. Multivariate analysis demonstrated that only subsequent treatment significantly influenced OS.

CONCLUSION

After surgery, SHC patients with subsequent treatment showed better outcomes. However, a more effective treatment is yet to be found. Further studies with a larger patient population are needed.

Distinct immunophenotypes and prognostic factors in renal cell carcinoma with sarcomatoid differentiation: a systematic study of 19 immunohistochemical markers in 42 cases

BACKGROUND

Renal cell carcinoma (RCC) with sarcomatoid differentiation is a relatively rare tumor containing both carcinoma and sarcomatoid components. However, there has not been a systemic study on immunophenotypes of renal cell carcinoma with sarcomatoid differentiation, especially using some renal specific immunohistochemical markers. In this study, we aimed to comprehensively investigate the distinct immunophenotypes of RCC with sarcomatoid differentiation to analyze the pathogenesis of sarcomatoid differentiation and identify new prognostic factors in RCC with sarcomatoid differentiation.

METHODS

A total of 42 cases of RCCs with sarcomatoid differentiation were enrolled into the study. Immunohistochemistry study was performed on tissue microarrays to evaluate the expressions of 19 immunohistochemical markers including a series of epithelial, mesenchymal markers and RCC specific markers. Kaplan-Meier method was applied to assess the prognostic values of CD10, CAIX, p53 and Bcl-2.

RESULTS

Histologically, 42 cases of RCCs with sarcomatoid differentiation presented with different proportions of carcinoma and sarcomatoid components. The cohort contained 35 cases of clear cell renal cell carcinoma (CCRCC) and 7 cases of chromophobe renal cell carcinoma (ChRCC) based on the carcinoma components. Immunohistochemically, all cases were positive for vimentin, and 80% of cases showed immunostaining for at least one epithelial marker, such as CK, EMA, CK7 and CK18. Notably, the expression rates of CAIX, CD10 and PAX8 in sarcomatoid cells were 76%, 76% and 64%, respectively. The carcinoma component of the tumors showed differentient labeling for CAIX, CD10, vimentin, CK7 and CD117 in CCRCC vs ChRCC, but the sarcomatoid component lost the specificity for these markers ( p < 0.05). Patients with positive expressions of CAIX, p53 and Bcl-2 had a poor prognosis.

CONCLUSIONS

The sarcomatoid cells in RCC with sarcomatoid differentiation express both epithelial and mesenchymal markers, supporting their epithelial origin. PAX8, CAIX and CD10 could be used as the reliable and useful markers to determine the renal origin of sarcomatoid cells such as in fine needle aspiration cases and metastatic RCC with sarcomatoid differentiation. CAIX, p53 and Bcl-2 might play important roles in the transformation from renal cell carcinoma to high malignant sarcomatoid differentiation, and these three immunohistochemical markers are adverse prognostic factors for the survival of patients with RCC with sarcomatoid differentiation.

Two cases of gallbladder metastasis from renal cell carcinoma and review of literature

Background

Renal cell carcinoma accounts for 90 % of renal neoplasms and metastatic disease is common. One third of newly diagnosed cases will have synchronous metastases at diagnosis and further 25–50 % will develop metachronous disease. 

Case Presentation

This study presents two new cases of gallbladder metastasis from renal cell carcinoma (RCC) from our institution and reviews the published literature. The final cohort included 52 evaluable patients. M/F ratio was 2:1 and median age was 62.5 years. Most patients were diagnosed incidentally after follow-up or staging imaging for RCC. Of the patients with available histology, all except one were clear cell type (n = 39) and 92 % were polypoid. Thirty-six patients demonstrated metachronous gallbladder metastasis with median disease-free interval (DFI) from nephrectomy of 4 years. The most frequent site of metastasis was the contralateral kidney (46.7 %) followed by the pancreas and lung. The median disease-free interval (DFS) after cholecystectomy was 37 months. Three- and five-year OS rates were 74 and 62 %, respectively. Age younger than 45 years (p = 0.008) and DFI <24 months (p = 0.049) were associated with decreased OS.

Conclusions

RCC metastasis to the gallbladder is associated with an unusual pattern of concomitant metastasis. Symptoms are not common. Simple cholecystectomy is associated with increased OS and nil local or port site recurrence. Young age and short DFI are associated with decreased OS.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-016-0843-3) contains supplementary material, which is available to authorized users.