Renal Cell Carcinoma Mimicking Transitional Cell Carcinoma: A Case Report

Patient: Female, 76-year-old

Final Diagnosis: Renal cell carcinoma

Symptoms: Flank pain • haematuria

Medication: —

Clinical Procedure: Nephroureterectomy

Specialty: Radiology • Urology

Oncological Outcomes of Patients With Different Pathological Features of pT3a Renal Tumor: A Systematic Review and Quantitative Synthesis

Purpose

To identify the differences in oncological outcomes for patients with different pT3a renal tumor invasion patterns and pathological features.

Methods

The protocol of this study was registered on PROSPERO (CRD42021234475). Relevant studies were identified by searching the PubMed, Cochrane library, Embase, and Web of Science databases. Cancer-specific survival (CSS) was selected as the endpoint. Pooled hazard ratio (HR) and 95% confidence interval (CI) extracted from multivariate Cox models were evaluated to identify the hazard association.

Results

A total of 22 studies, which enrolled 12384 patients were included for quantitative synthesis. Sinus fat invasion (SFI) + perinephric fat invasion (PFI) was associated with inferior CSS compared to SFI only (p = 0.02). Comparable CSS was observed between SFI and PFI (p = 0.57). SFI ± PFI showed inferior CSS compared to PFI only (p = 0.0002). The presence of pelvicalyceal system invasion significantly increased the risk of cancer-specific mortality (p = 0.0005). Renal vein invasion (RVI) indicated poor oncological outcomes in terms of CSS (p = 0.002). The concomitant RVI and fat invasion (FI) significantly increased the risk of deterioration of CSS compared to RVI or FI (p < 0.0001). Multiple invasion patterns translated into a significantly decreased CSS (p < 0.0001). Aggressive tumor behavior, including lymph node involvement (p = 0.006), distant metastases (p < 0.00001), sarcomatoid differentiation (p < 0.0001), necrosis (p < 0.0001), Fuhrman grade III or IV (p < 0.0001), positive margin (p < 0.0001), and tumor size >7cm (p < 0.0001) were the predictors of inferior CSS. The lymphovascular invasion (p = 0.67) was indolent in terms of CSS.

Conclusion

This study confirmed the heterogenicity of pT3a renal tumors. Multiple invasion patterns could translate into a significantly decreased CSS, and SFI should not be merged in the SFI + PFI group. The presence of PSI or RVI could significantly increase the risk of cancer-specific mortality. Lymph node involvement, distant metastases, sarcomatoid differentiation, necrosis, high Fuhrman grade, positive margin, and size >7cm were the predictors of inferior CSS. A precise-risk grade of CSS for different invasion patterns including comprehensive combinations may be useful for the further refinements of the TNM system.

Systematic Review Registration

The current study was registered on PROSPERO, and the registration numbers is CRD42021234475.

Urinary collecting system invasion on multiphasic CT in renal cell carcinomas: prevalence, characteristics, and clinical significance

PURPOSE

The aim of this study was to determine the prevalence of collecting system invasion (CSI) on multiphasic CT, validate the pathological findings, and investigate the relationship between CSI and clinical outcomes in patients with renal cell carcinomas (RCC).

METHODS

Patients pathologically diagnosed with RCC between January 2008 and December 2017 were retrospectively enrolled in this study. They were divided into two groups according to the presence of CSI on multiphasic CT images. Patients' clinical characteristics, radiological findings, and overall survival (OS) and recurrence-free survival (RFS) rates were analyzed and compared between the groups. In addition, the correlation of radiological findings with pathological findings was investigated.

RESULTS

Among the included 347 kidneys of 340 patients, CSI was observed in 11 kidneys (3%; 95% confidence interval, 1.3-5.0%). In all the 11 kidneys, the tumors were pathologically diagnosed as clear cell RCC, and in one kidney, the tumor also had sarcomatoid features. When pathological CSI served as the standard of reference, the sensitivity, specificity, and accuracy of CSI on CT were 50%, 99.7%, and 97.1%, respectively. The OS and RFS rates were not significantly different between patients with CSI on CT and those without CSI.

CONCLUSION

This study found that the prevalence of RCC-related CSI was 3%. Because of the low prevalence, we cannot exclude the possibility that CSI on CT would be associated with the OS and RFS. Further studies are needed to determine whether CSI on CT can be an independent prognostic factor for survival in patients with RCC.

Renal neoplasia with papillary architecture involving the pelvicalyceal system

Pelvicalyceal system (PS) involvement by renal cell carcinoma (RCC) is staged as pT3a disease (American Joint Committee on Cancer [AJCC], 8th edition). As papillary RCC (PRCC) has been infrequently represented in studies looking at the prognostic impact of PS involvement, we reviewed our institutional cohort of 8225 cases for PS involvement by PRCC. Nine such cases were subjected to histopathologic review and immunohistochemistry. Fluorescence in situ hybridization for TFE3/TFEB alterations was performed if indicated. One case each (1 of 9, 11%) was classified as TFE3-rearranged and FH-deficient RCC. The majority were high grade (World Health Organization/International Society of Urologic Pathology grade 3: 8 of 9, 89%) or had features of aggressive disease, including hilar fat (6 of 9, 67%) and regional lymph node involvement (5 of 7, 71%). One low-grade 3.3-cm tumor with isolated PS involvement with a germline heterozygous FH p.Lys477dup alteration with retained FH, lack of increased S-(2-succino)-cysteine expression, BRAF V600E immunohistochemistry positivity, and lack of trisomy 7/17 on chromosomal microarray was identified, arguing against an FH-deficient and conventional PRCC. Our study shows that PS involvement by renal neoplasia with papillary architecture is a rare event. Aside from PRCC, it is important to note that these may include other aggressive and nonaggressive subtypes of renal neoplasia with papillary architecture. One case of isolated PS involvement by a low-grade, noninvasive tumor that we refer to as nephrogenic papillary neoplasm was identified. At present, there are insufficient data to stage such tumors as pT3a (AJCC, 8th edition), and additional studies are needed to address this question.

Staging of renal cell carcinoma: current progress and potential advances

Formal staging classifications for renal cell carcinoma (RCC) were first proposed in 1978 and were incorporated into the Tumour, Nodes, Metastases (TNM) system initially published by the Union Internationale Contre le Cancer (UICC) in 1978. There has been a gradual evolution of grading criteria through six separate editions of the UICC TNM Classification, with the latest edition being published in 2016. Somewhat surprisingly there were no changes to the T category criteria from the 2009 to the 2016 editions of the classification, although an erratum has subsequently been published that incorporated the minor changes included in the eighth edition of the TNM Classification published by the American Joint Committee on Cancer. Localised tumours are staged according to the size of the primary tumour, with the TNM classification recognising that these tumours may exceed 10 cm in diameter. This is unfortunate as there is good evidence to demonstrate that, for clear cell RCC, virtually all tumours >7 cm in diameter and a substantial proportion of tumours <7 cm in diameter, show extra-renal spread. Infiltration of tumour beyond the renal capsule into the peri-renal fat is also categorised as T3a, however the clinical importance of this remains unclear. The classification of microvascular invasion within the renal sinus requires clarification, as does the prognostic significance of tumour in small vessels within the kidney.

Prognostic effect of renal collecting system invasion on survival of patients with renal cell carcinoma and tumor thrombus

Introduction

Urinary collecting system invasion (UCSI) has been found to have significant prognostic value for patients with renal cell carcinoma (RCC). However, for RCC patients with venous tumor thrombus (VTT), only contradictory data exist regarding the prognostic efficacy of UCSI. Therefore, the aim of this study is to assess the prognostic relevance of UCSI in survival of patients with RCC and VTT.

Material and methods

Medical records in a prospectively maintained institutional database were analyzed for RCC-VTT patients who had undergone nephrectomy with thrombectomy. Then, the effect of UCSI on overall survival was analyzed.

Results

The study examined data for 114 patients, including patients with VTT present in the renal vein (35 patients, 31%), infrahepatic inferior vena cava (28 patients, 24%), and suprahepatic inferior vena cava (51 patients, 45%). Nineteen percent of patients had UCSI. The median overall survival of patients with UCSI was 9 months, whereas median overall survival was 10 months for patients without collecting system invasion. Survival and regression analyses rejected UCSI as a prognostic marker for overall survival.

Conclusions

UCSI has no effect on survival in our cohort of RCC-VTT patients. Therefore, it should not be considered in risk stratification models or in treatment decision-making for this patient group.

Evaluation of individual and cumulative sites of extrarenal tumor invasion in pT3a clear cell renal cell carcinoma

INTRODUCTION

The Tumor-Node-Metastasis classification of renal cell carcinoma (RCC) for pT3a tumors includes sinus fat invasion (SFI), perinephric fat invasion (PFI), renal vein invasion (RVI), and/or pelvicaliceal system invasion (PSI). The purpose of this study was to determine the association between these patterns of invasion (assessed individually and cumulatively) with the development of metastases and cancer-specific mortality (CSM).

MATERIALS AND METHODS

We identified 160 patients who underwent radical nephrectomy for pT3a clear cell RCC between 2011 and 2017. The association between individual patterns of invasion and metastases and cancer-specific survival were evaluated with multivariate logistic regression. Cox Hazard proportion ratios and Kaplan-Meier survival curves were generated for patterns of invasion (assessed individually and cumulatively).

RESULTS

The number of individual invasive patterns was as follows: 97/160 (61%) presented with RVI, 91/160 with SFI (57%), 62/160 with PFI (39%), and 24/160 (15%) with PSI. At multivariate analysis, both PFI and RVI were associated with metastases (P < 0.001 and 0.028, respectively). PFI (hazard ratio [HR] 4.12, 95% confidence interval [CI] 2.14-7.92; P < 0.001), RVI (HR 2.44, 95% CI 1.18-5.01; P = 0.015), SFI (HR 2.13, 95% CI 1.05-4.34; P = 0.036) had higher CSM, while PSI (HR 1.43, 95% CI 0.65-3.16; p = 0.38) did not show increased CSM. Furthermore, cumulative analysis showed that multiple invasive patterns resulted in worse CSM (p < 0.001).

CONCLUSIONS

In our study, PFI was associated with the most aggressive behavior while PSI was the most indolent. Furthermore, the presence of more than one pattern of invasion was associated with worse CSM. These results indicate that reporting of the individual location and cumulative amount of pT3a patterns of invasion in clear cell RCC is clinically relevant.

Renal cell carcinoma staging: pitfalls, challenges, and updates

Renal cell carcinoma (RCC) is unusual among cancers in that it often grows as a spherical, well-circumscribed mass. Increasing tumour size influences the pathological pT stage category within pT1 and pT2, with cutoffs of 40, 70 and 100 mm; however, with increasing size also comes a sharp increase in the likelihood of renal sinus or renal vein tributary invasion, such that clear cell RCC rarely reaches 70 mm without invading one of these. To clarify some previous challenges in assigning tumour stage, the American Joint Committee on Cancer 2016 tumor-node-metastasis classification has removed the requirements than vein invasion be recognised grossly and that vein walls contain muscle for the diagnosis of vein invasion. Renal pelvis invasion has also been added as an additional route to pT3a. Multinodularity or finger-like extensions from a renal mass should be viewed with great suspicion for the possibility of vein or renal sinus invasion, and, as tumour size increases to over 40-50 mm, thorough sampling of the renal sinus interface should always be undertaken. With increasing interest in adjuvant therapy in renal cancer, the pathologist's role in RCC staging will continue to be an important prognostic parameter and a tool for selection of patients for enrolment in clinical trials.

WHO/ISUP classification, grading and pathological staging of renal cell carcinoma: standards and controversies

PURPOSE

Pathological parameters assessed on biopsies and resection specimens have a pivotal role in the diagnosis, prognosis and management of patients with renal cell carcinoma (RCC).

METHODS

A non-systematic literature search was performed, updated to January 2018, to identify key standards and controversies in the pathological classification, grading and staging of RCC.

RESULTS

Although most RCCs exhibit characteristic morphology that enables easy categorisation, RCCs show considerable morphological heterogeneity and it is not uncommon for there to be difficulty in assigning a tumour type, especially with rarer tumour subtypes. The differentiation between benign and malignant oncocytic tumours remains a particular challenge. The development of additional immunohistochemical and molecular tests is needed to facilitate tumour typing, because of the prognostic and therapeutic implications, and to enable more reliable identification of poorly differentiated metastatic tumours as being of renal origin. Any new tests need to be applicable to small biopsy samples, to overcome the heterogeneity of renal tumours. There is also a need to facilitate identification of tumour types that have genetic implications, to allow referral and management at specialist centres. Digital pathology has a potential role in such referral practice.

CONCLUSION

Much has been done to standardise pathological assessment of renal cell carcinomas in recent years, but there still remain areas of difficulty in classification and grading of these heterogeneous tumours.

Renal cell carcinoma and pathologic nodal disease: Implications for American Joint Committee on Cancer staging

BACKGROUND

Lymph node (LN) metastases are associated with poor outcomes for patients with renal cell carcinoma (RCC). This study compared the survival outcomes of patients with stage III, node-positive disease (pT₁₂₃ N₁ M₀ ) and patients with stage III, node-negative disease (pT₃ N₀ M₀ ).

METHODS

A database of 4652 patients with RCC of any histological subtype treated with surgery at The University of Texas MD Anderson Cancer Center from 1993 to 2012 was retrospectively assessed. A total of 115 patients with pT₁₂₃ N₁ M₀ disease, 274 patients with pT₃ N₀ M₀ disease, and 523 patients with pT₁₂₃ N_0/x M₁ disease were included. Overall survival (OS) and cancer-specific survival (CSS) were estimated and compared between each cohort.

RESULTS

Median OS and CSS times were significantly better for pT₃ N₀ M₀ patients than pT₁₂₃ N₁ M₀ patients (OS, 10.2 vs 2.4 years, P < .0001; CSS, not reached vs 2.8 years, P < .0001). Similar median OS and CSS times were noted for pT₁₂₃ N₁ M₀ and pT₁₂₃ N_0/x M₁ patients (OS, 2.4 vs 2.4 years; P = .62; CSS, 2.8 vs 2.4 years; P = .10). In a multivariate analysis, tumor grade (hazard ratio [HR] for OS, 2.47; P < .0001; HR for CSS, 2.99; P < .0001) and pathologic LN involvement (HR for OS, 2.44; P < .0001; HR for CSS, 2.85; P < .0001) were associated with worse OS and CSS.

CONCLUSIONS

Among RCC patients classified with stage III disease, those with pT₁₂₃ N₁ M₀ disease had significantly worse survival than those with pT₃ N₀ M₀ disease. OS and CSS were similar for patients with pT₁₂₃ N₁ M₀ disease and patients with pT₁₂₃ N_0/x M₁ disease (stage IV). If validated, these findings suggest that RCC patients with nodal disease should be reclassified as having stage IV disease.