Renal mass biopsy for the small renal mass

Rapid on-site evaluation in percutaneous core needle biopsies of renal masses: Cytologic-histologic concordance and diagnostic challenges

BACKGROUND

Image-guided fine needle aspirations (FNAs) and core needle biopsies (CNBs) play the critical role in diagnosis of renal lesions. Rapid on-site evaluation (ROSE) can potentially increase the adequacy rate and improve diagnostic yield, while providing additional information for rapid clinical decisions. The aim of this study is to evaluate the diagnostic utility of ROSE in obtaining adequate tissue for diagnosis of renal lesions in our institution.

METHODS

We retrospectively reviewed all percutaneous renal CNB cases with available ROSE interpretations for a 11-year period. The ROSE interpretations and CNB diagnoses was compared and the concordance rate was calculated accordingly. The discrepant cases were re-reviewed and the possible causes for discrepancy were analyzed.

RESULTS

A total of 189 cases were identified. Definitive diagnoses were rendered in 164 (87%) cases on the final CNBs, including primary renal lesions in 151 cases and metastatic malignancies in 13 cases. At the time of ROSE, samples were deemed to be adequate in the majority of cases (83%). The calculated concordance rate between ROSE interpretations and CNB final diagnoses was 84.6%. Sampling issue and scant tumor cells were the main causes for the discordance between ROSE interpretations and CNB diagnoses.

CONCLUSION

Our study showed a relatively high-concordance rate of 84.6% between ROSE interpretations and CNB final diagnoses, suggesting that ROSE is a valuable tool for procurement of adequate renal CNB samples for diagnosis.

Ultrasound-Guided Renal Mass Biopsy and Its Clinical Utility: A Single-Centre Experience

INTRODUCTION

Renal mass biopsy (RMB) is still underutilized, partially because many urologists argue that it does not substantially influence the management of renal masses. We sought to evaluate the influence of RMB on the management of renal tumours in our institution.

MATERIALS AND METHODS

A total of 387 RMBs performed at our institution from January 2016 to June 2020 were included. Patient demographics, mass size, biopsy result, and subsequent clinical management were retrospectively reviewed.

RESULTS

The mean mass size was 47.8 mm. Fifty-six percentage of tumours ≤40 mm (247) and 8% of tumours >40 mm (64) were biopsied. Seventy-six RMBs of disseminated tumours were performed. 14.9% of RMBs were non-diagnostic, and 27.1% of RMBs of tumours ≤40 mm were benign. The majority of tumours with first non-diagnostic RMB followed by histopathological verification were found to be malignant. There was significantly more conservative management and no radical nephrectomies in the benign biopsy group. One case of Clavien-Dindo grade ≥2 complication occurred.

CONCLUSIONS

RMB result affects treatment decisions. Ultrasound-guided RMB is a safe procedure, and performing biopsies of tumours ≤40 mm may reduce the number of unnecessary interventions. Non-diagnostic RMBs should be repeated or treated as malignant.

Touch preparation for rapid onsite evaluations of renal mass biopsies: concordance rate, pearls, and pitfalls

INTRODUCTION

Core needle biopsy (CNB) of renal masses has not been commonly performed because of the perceived low sensitivity until recent years. Rapid onsite evaluation (ROSE) using touch preparations (TPs) has the potential to improve the yield of CNB, although it can be challenging because of the diverse morphology of various types of renal tumors and native cells.

MATERIALS AND METHODS

We retrospectively reviewed percutaneous CNBs of renal masses with ROSE using TPs. ROSE findings were correlated with diagnoses on CNBs.

RESULTS

Among the 165 cases identified between August 2016 and August 2019, CNB led to definitive diagnoses in 82.4% (136 of 165) cases. These included renal cell carcinomas (RCCs) (n = 113, 68.5%), benign neoplasms (n = 14, 8.5%), urothelial carcinomas (n = 6, 3.6%), metastatic carcinomas (n = 2, 1.2%) and 1 case of lymphoma (0.6%). Eight cases were indeterminate, including 2 cases positive for oncocytic neoplasm, 2 cases suspicious for RCC, and 4 cases with atypical features. Twenty-one (12.7%) CNBs were negative for tumor. ROSE interpretations for these cases were: malignant (n = 18, 10.8%); positive for neoplasm (n = 6, 3.6%); atypical/lesional/adequate not otherwise specified (n = 113, 68.5%); negative (n = 19, 11.5.0%); and unsatisfactory (n = 9, 5.5%). The overall concordance rate between ROSE and the final CNB diagnoses was 87.3%.

CONCLUSIONS

Renal mass CNBs revealed a subset of non-surgical conditions in addition to RCCs. ROSE using TPs showed a high concordance rate with CNB results. Proximal tubular cells, macrophages, and angiomyolipomas are common pitfalls, whereas vacuolated cytoplasm and background are helpful features to confirm low-grade RCCs.

Outcomes and predictors of benign histology in patients undergoing robotic partial or radical nephrectomy for renal masses: a multicenter study

Introduction

Theaim of this study was to assess preoperative factors associated with benign histology in patients undergoing surgical removal of a renal mass and to analyze outcomes of robotic partial nephrectomy (PN) and radical nephrectomy (RN) for these masses.

Material and methods

Overall, 2,944 cases (543 benign and 2,401 malignant) who underwent robotic PN and RN between 2003–2018 at 10 institutions worldwide were included. The assessment of the predictors of benign histology was made at the final surgical pathology report. Descriptive statistics, Mann-Whitney U, Pearson’s χ², and logistic regression analysis were used.

Results

Patients in the benign group were mostly female (61 vs. 33%; p <0.001), with lower body mass index (BMI) (26.0 vs. 27.1 kg/m²; p <0.001). The benign group presented smaller tumor size (2.8 vs. 3.5 cm; p <0.001), R.E.N.A.L. score (6.0 vs. 7.0; p <0.001). There was a lower rate of hilar (11 vs.18%; p = 0.001), cT≥3 (1 vs. 4.5%; p <0.001) tumors in the benign group. There was a statistically significant higher rate of PN in the benign group (97 vs. 86%; p <0.001) as well as a statistically significant lower 30-day re-admission rate (2 vs. 5%; p = 0.081). Multivariable analysis showed male gender (OR: 0.52; p <0.001), BMI (OR: 0.95; p <0.001), and cT3a (OR: 0.22; p = 0.005) to be inversely associated to benign histology.

Conclusions

In 18% of cases, a benign histologic type was found. Only 3% of these tumors were treated with RN. Female gender, lower BMI, and higher T staging showed to be independent predictors of benign histology.

Searching for prognostic biomarkers for small renal masses in the urinary proteome

Renal cell carcinoma (RCC) is frequently diagnosed incidentally as an early-stage small renal mass (SRM; pT1a, ≤4 cm). Overtreatment of patients with benign or clinically indolent SRMs is increasingly common and has resulted in a recent shift in treatment recommendations. There are currently no available biomarkers that can accurately predict clinical behavior. Therefore, we set out to identify early biomarkers of RCC progression. We employed a quantitative label-free liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) proteomics approach and targeted parallel-reaction monitoring to identify and validate early, noninvasive urinary biomarkers for RCC-SRMs. In total, we evaluated 115 urine samples, including 33 renal oncocytoma (≤4 cm) cases, 30 progressive and 26 nonprogressive clear cell RCC (ccRCC)-SRM cases, in addition to 26 healthy controls. We identified six proteins, which displayed significantly elevated expression in clear cell RCC-SRMs (ccRCC-SRMs) relative to healthy controls. Proteins C12ORF49 and EHD4 showed significantly elevated expression in ccRCC-SRMs compared to renal oncocytoma (≤4 cm). Additionally, proteins EPS8L2, CHMP2A, PDCD6IP, CNDP2 and CEACAM1 displayed significantly elevated expression in progressive relative to nonprogressive ccRCC-SRMs. A two-protein signature (EPS8L2 and CCT6A) showed significant discriminatory ability (areas under the curve: 0.81, 95% CI: 0.70-0.93) in distinguishing progressive from nonprogressive ccRCC-SRMs. Patients (Stage I-IV) with EPS8L2 and CCT6A mRNA alterations showed significantly shorter overall survival (p = 1.407 × 10^-6 ) compared to patients with no alterations. Our in-depth proteomic analysis identified novel biomarkers for early-stage RCC-SRMs. Pretreatment characterization of urinary proteins may provide insight into early RCC progression and could potentially help assign patients to appropriate management strategies.

Diagnostic Performance of Ultrasound Shear Wave Elastography in Solid Small (≤4 cm) Renal Parenchymal Masses

The aim of the study was to analyze the diagnostic performance of shear wave elastography (SWE) in differentiating between malignant and benign solid renal parenchymal masses ≤4 cm, compared with conventional ultrasound. A total of 20 healthy volunteers and 117 patients had been included in this study. Conventional ultrasound and SWE were performed in all volunteers and patients. The elasticity of healthy cortex and the elastic parameters of tumors such as mean elasticity (E_mean), minimum elasticity (E_min), maximum elasticity (E_max), standard deviation and elasticity ratio of the lesion to surrounding cortex (E_ratio) were measured on SWE images. Diagnostic performance of SWE was compared with that of conventional ultrasound. The cortical elasticity values of healthy right and left kidneys were 4.7 ± 1.7 and 4.5 ± 1.5 kPa, respectively. Of the 117 renal tumors, 68 were renal cell carcinomas (RCCs) and 49 were benign. E_mean, E_min and E_ratio were significantly lower in RCCs compared with benign lesions: E_mean 7.2 ± 2.5 kPa versus 10.0 ± 2.4 kPa, E_min 2.5 ± 2.4 kPa versus 5.6 ± 2.3 kPa, E_ratio 1.6 ± 0.5 versus 2.2 ± 0.6 (all p values < 0.001). The cutoff values of 9.15 kPa for E_mean, 3.55 kPa for E_min and 1.99 for E_ratio had the highest areas under the receiver operating characteristics curve (0.801 for E_mean, 0.832 for E_min and 0.806 for E_ratio). Combining E_mean, E_min and E_ratio with conventional ultrasound improved the specificity for predicting RCCs to 87.8%, but the sensitivity was not increased.

Harnessing the Genomic Landscape of the Small Renal Mass to Guide Clinical Management

CONTEXT

Small renal masses (SRMs; tumors <4 cm) encompass a diagnostic and therapeutic challenge. Genomic profiling has the potential to improve risk stratification and personalize treatment selection.

OBJECTIVE

Herein, we review the evidence regarding the utility, challenges, and potential implications of genomic profiling in the management of SRMs.

EVIDENCE ACQUISITION

Pertinent publications available on PubMed database pertaining to kidney cancer, tumor size, genomics, and clinical management were reviewed.

EVIDENCE SYNTHESIS

Compared with larger tumors, SRMs range from benign to lethal, necessitating strategies for improved treatment selection. Recent advances in the molecular characterization of renal cell carcinoma have improved our understanding of the disease; however, utility of these tools for the management of SRMs is less clear. While intratumoral heterogeneity (ITH) reduces the accuracy and reliability of sequencing, relative genomic uniformity of SRMs somewhat lessens the impact of ITH. Therefore, renal mass biopsy of SRMs represents an appealing opportunity to evaluate how incorporation of molecular profiles may improve management strategies.

CONCLUSIONS

Ongoing research into the genomic landscape of SRMs has advanced our understanding of the spectrum of disease aggressiveness and may hold promise in matching disease biology to treatment intensity.

PATIENT SUMMARY

Small renal masses are a clinical challenge, as they range from benign to lethal. Genomic profiling may eventually improve treatment selection, but more research is needed.

Histologic Diagnosis of Renal Mass Biopsy

CONTEXT.—

Core biopsy has been increasingly used for clinical decision-making in the management of patients with renal masses. The sensitivity and specificity of histologic diagnoses of renal mass biopsies depend on many factors such as adequate sampling and tissue processing, diagnostic skill and experience, and appropriate use of ancillary techniques.

OBJECTIVE.—

To review the indications, emphasize the importance of obtaining adequate diagnostic material, and introduce a general diagnostic approach, in conjunction with immunohistochemistry, in diagnosis of renal mass biopsies.

DATA SOURCES.—

Literature review and personal experiences in daily practice and consultation diagnosis of renal masses in a large tertiary medical center.

CONCLUSIONS.—

For renal mass biopsies, it is critical to obtain adequate diagnostic material and establish a standard laboratory procedure in working with small biopsy specimens. The key for the diagnosis is to be familiar with different tumor entities with characteristic morphology and to understand the wide spectrum of tumor heterogeneity. By developing a systematic approach, one can categorize the tumor and create a sensible differential diagnosis based on the growth pattern and cellular morphology. Immunohistochemistry is particularly helpful for renal mass biopsy diagnosis in selected situations.