Renal mass biopsy: A strategy to reduce associated costs and morbidity when managing localized renal masses

Treatment Modalities and Risks of Complication for Patients With Localized Renal Cell Carcinoma Aged 75 and Older

BACKGROUND AND OBJECTIVES

Partial (PN)/radical (RN) nephrectomy is the standard treatment for localized renal-cell carcinoma (RCC). The potential risks of these procedures are concerns for the elderly. We evaluated perioperative outcomes/survival for patients aged ≥ 75 years with localized RCC who underwent PN, RN, or thermal ablation (TA).

METHODS

Localized RCC patients undergoing PN/RN/TA (2000-2023) were retrospectively reviewed. Logistic-regression assessed factors associated with major complications. Kaplan-Meier estimated survival.

RESULTS

A total of 278 patients (≥ 75 years) with RCC who received intervention (107RN, 101PN, and 70TA) were identified. Median age was 78 years. PN patients were younger than other cohorts (77 vs. 79, p = 0.006). Patients with cancer comorbidities underwent TA than PN/RN (93% vs. 88%/76%, respectively). Median tumor size was 4.0, 3.0, and 2.6 cm in RN, PN, and TA cohorts, respectively. RN patients had more complex masses compared to other cohorts (9 vs. 7, p < 0.001). Postoperative complications were significantly greater among PN patients (p = 0.03), but there was no significant difference in Clavien ≥ 3 complications. Peripheral vascular disease (PVD) was associated with Clavien ≥ 3 complications on multivariable analysis (p = 0.03). RN was performed at a stable rate while PN decreased in favor of TA. There was no significant difference in RCC-/non-RCC-specific survival among treatment modalities.

CONCLUSIONS

It is important to make informed decisions about treating RCC in the elderly to reduce morbidity/mortality. PVD could be a determining factor favoring TA for amenable tumors.

Renal Cell Carcinoma: A Review

Importance

Renal cell carcinoma (RCC) is a common malignancy, with an estimated 434 840 incident cases worldwide in 2022. In the US, it is the sixth most common cancer among males and ninth among females.

Observations

Clear cell RCC is the most common histologic subtype (75%-80% of cases) and is characterized by inactivation of the von Hippel Lindau (VHL) tumor suppressor gene. Many patients (37%-61%) are diagnosed with RCC incidentally on an abdominal imaging study such as ultrasound or computed tomographic scan, and 70% of patients have stage I RCC at diagnosis. Although its incidence has increased approximately 1% per year from 2015 through 2019, the mortality rate of RCC has declined about 2% per year in the US from 2016 through 2020. Patients with a solid renal mass or complex cystic renal mass should be referred to urology. Treatment options for RCC confined to the kidney include surgical resection with partial or radical nephrectomy, ablative techniques (eg, cryoablation, radiofrequency ablation, radiation), or active surveillance for some patients (especially those with renal masses <2 cm). For patients with renal masses less than 4 cm in size (48% of patients), partial nephrectomy can result in a 5-year cancer-specific survival of more than 94%. For advanced or metastatic RCC, combinations of immune checkpoint inhibitors or the combination of immune checkpoint inhibitors with tyrosine kinase inhibitors are associated with tumor response of 42% to 71%, with a median overall survival of 46 to 56 months.

Conclusions and Relevance

RCC is a common malignancy that is often diagnosed incidentally on an abdominal imaging study. Seventy percent of patients are diagnosed with stage I RCC and 11% of patients with stage IV. First-line treatments for early-stage RCC are partial or radical nephrectomy, which can result in 5-year cancer-specific survival of more than 94%, ablative techniques, or active surveillance. New treatment options for patients with metastatic RCC include immune checkpoint inhibitors and tyrosine kinase inhibitors.

Diagnostic accuracy and clinical impact of renal biopsy cytology

BACKGROUND

The role of fine needle biopsy cytology in the workup of renal mass lesions remains controversial. With advances in imaging technology and clinical management for renal masses, a critical reevaluation of the role of renal biopsy is needed. This study was designed to provide a comprehensive evaluation of the performance and clinical impact of fine needle biopsy in patients with renal masses.

METHODS

A 5-year retrospective study of ultrasound or computer tomography (CT)-guided fine needle biopsies of renal masses diagnosed via cytopathology was conducted. Overall diagnostic rate, sensitivity, and diagnostic accuracy were calculated. Further analysis of the impact of fine needle biopsy cytology on clinical management was performed.

RESULTS

A total of 227 cases of fine-needle aspiration and/or biopsy (FNA/B) of renal masses were identified, including 76 with subsequent nephrectomies. Complications were rare (<1%). The diagnostic rate and sensitivity of FNA/B were 83.3% and 89.5%, respectively. Diagnostic accuracy was 98.7% at the major categorical level and 94.7% at the tumor subtype level. Subsequent clinical actions were associated with a definitive cytologic diagnosis of malignancy/neoplasia (p < .05) and were affected by tumor subtype (p < .05).

CONCLUSION

This study demonstrates that FNA/B of renal masses is a safe and reliable minimally invasive diagnostic tool with excellent accuracy in confirmation of malignancy and subclassification of tumors. Diagnoses made on FNA/B play a key role in guiding a personalized clinical treatment plan.

Utilization of Re-VASC, the Novel Retroperitoneal Neovascularity Scoring System, for Characterization of T1a Small Renal Masses

Purpose: Early characterization of small (T1a, <4 cm) renal masses is imperative for patient care and treatment planning. Renal biopsy is a sensitive and specific procedure that can accurately differentiate small renal masses as malignant or benign. However, it is an invasive procedure with a nonnegligible complication rate and is not performed routinely at most institutions. In this study, we sought to apply the Retroperitoneal Vascularity Assessment and Scoring in Carcinoma (Re-VASC) scoring system to T1a renal masses and analyzed whether it could differentiate these masses as benign or malignant. Methods: We obtained Institutional Review Board approval to retrospectively examine the records of all patients who presented to our single, urban academic referral center for surgical treatment of renal cell carcinoma (RCC). For the malignant group, patients with a diagnosis of T1a RCC from pathologic evaluation were included. Additionally, patients with a histopathological diagnosis of a T1a nonmalignant renal mass (fat poor-angiomyolipoma or oncocytoma) were included in our benign group. Results: This study includes 57 benign and 69 malignant T1a renal tumors. Average size for benign and malignant masses were 2.47 and 2.63, respectively (p = 0.267). Analysis demonstrated no significant difference between both groups in terms of sex, laterality, or size. The average Re-VASC score of benign and malignant masses was 0.175 and malignant masses was 0.784, respectively (p < 0.001). Additionally, the Re-VASC score was independently associated with malignancy with an odds ratio of 2.223 (p = 0.0109). Conclusion: The Re-VASC scoring system exhibits significantly greater values for malignant T1a renal masses when compared to benign masses. As a result, it shows promise as an adjunctive tool to renal biopsy for clinical decision-making. Further assessment of Re-VASC's true efficacy as a diagnostic marker will include prospective evaluation of a larger multicenter population.

Concordance between renal tumour biopsy and robotic-assisted partial and radical nephrectomy histology: a 10-year experience

We aimed to assess concordance between renal tumour biopsy (RTB) and surgical pathology from robotic-assisted partial nephrectomy (RAPN) or robotic-assisted radical nephrectomy (RARN). Patients with preoperative RTB undergoing RAPN or RARN for suspected malignancy (9 September 2013-9 September 2023) were enrolled retrospectively from three sites. Patients were excluded if the tumour had prior cryotherapy or if biopsy or nephrectomy histology were unavailable or inconclusive. The primary outcome was concordance with the presence/absence of malignancy. Secondary outcomes were concordance with tumour subtype, World Health Organisation nuclear grade (patients with RTB clear cell or papillary RCC only), false-negative rate, false-positive rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). In the enrolment period, 332 and 132 patients underwent RAPN and RARN, respectively. Of these, 160 received preoperative RTB, with nine patients excluded, leaving 151 eligible patients. Median age was 63 years, and 49 (32%) were female. On surgical specimens, 144 patients had malignant histology. RTB was highly concordant with presence/absence of malignancy (147/151, 97%). Concordance with tumour subtype occurred in 141 patients (93%), while concordance with nuclear grade was seen in 42/66 patients (64%, RTB grade missing in 53 patients). False-negative rate, false-positive rate, sensitivity, specificity, PPV, and NPV were 2%, 14%, 98%, 86%, 99%, and 67%, respectively. Limitations include absence of complication data and exclusion of patients biopsied without surgery. In patients undergoing RAPN or RARN, preoperative RTB has high concordance with surgical pathology, both in the presence of malignancy and RCC subtype.

Reliability and Management Outcomes Following a Percutaneous Biopsy Diagnosis of Oncocytoma: A 15-year Retrospective Analysis

Background There is uncertainty in the management of renal masses diagnosed as oncocytomas with image-guided percutaneous biopsy. Purpose To assess the reliability of a diagnosis of oncocytoma based on image-guided percutaneous renal mass biopsy and evaluate patient outcomes following different management strategies. Materials and Methods In this retrospective study, image-guided percutaneous biopsy pathology reports from April 2004 to April 2019 were searched for keywords "oncocytoma" and "oncocytic neoplasm" and compared with surgical pathology or repeat biopsy results. Patients with at least 12 months of clinical follow-up and known cause of death were grouped according to management strategies, and disease-specific survival and metastatic renal cell carcinoma (RCC)-free survival were compared. Mass growth rates were calculated with use of a normal linear mixed model. Results The database yielded 160 biopsy reports of 149 renal masses in 139 patients; 149 masses were categorized as oncocytoma (n = 107), likely oncocytoma (n = 12), oncocytic neoplasm (n = 28), and indeterminate with oncocytoma in differential (n = 2). Biopsied masses categorized as oncocytoma or likely oncocytoma were oncocytomas in 16 of 17 masses (94%) based on surgical pathology or repeat biopsy; four of eight masses (50%) categorized as oncocytic neoplasms were low-grade RCCs. Outcome analysis included 121 patients (mean age ± SD, 68 years ± 9.1; 82 men); 80 patients initially underwent active surveillance (11 were later treated), 33 underwent ablation, and eight underwent surgery. Disease-specific survival and metastatic-free survival were 100% after each management strategy (median follow-up, 86.6 months; range, 14.2-207.9 months). Mass growth rate (mean, 1.7 mm per year) showed no evidence of a significant difference among biopsy result categories (P = .37) or initial (P = .84) or final management strategies (P = .11). Conclusion Image-guided percutaneous biopsy diagnosis of renal oncocytoma was reliable. Although some masses diagnosed as oncocytic neoplasms were low-grade renal cell carcinomas (RCCs) at final diagnosis, no patients died of RCC, including those managed with active surveillance. © RSNA, 2023 See also the editorial by Lockhart in this issue.

Renal Mass Biopsy

Kidney cancer accounts for 2% of cancer related deaths. Historically, a patient with a solid renal mass would undergo surgery without biopsy given the previously low diagnostic yield of biopsy and the fear of tumor seeding. This led to a high rate of resection for benign masses. With the rising incidence of renal masses discovered on imaging, improvements in biopsy technique and advancements in pathologic evaluation of biopsy samples of renal masses, renal mass biopsy now plays an important role in selected patients with renal masses. Coaxial core needle biopsy is the preferred technique with a low rate of complications and a high diagnostic yield. This article will discuss indications, methods, utility, limitations and complications of renal mass biopsy.