Renal Mass Biopsy—A Renaissance?

Purpose

Advances in our understanding of the natural history and limited aggressive potential of many small renal masses, expanding treatment options and the integration of molecular factors into prognostic and therapeutic algorithms have stimulated renewed interest in percutaneous renal mass biopsy.

Materials and Methods

A comprehensive literature review was performed using MEDLINE®/PubMed® to evaluate the indications, techniques, complications and efficacy of renal mass biopsy.

Results

Reported techniques of renal mass biopsy vary widely with different modes of radiographic guidance, needle size, number of cores and pathological analyses. Percutaneous renal mass biopsy with 2 or 3 cores using 18 gauge needles may improve diagnostic accuracy without increasing morbidity. Serious complications of percutaneous biopsy are rare and the minor complication rate in recent series has been less than 5%. The reported rate of technical failure of renal mass biopsy due to insufficient material was about 9% before 2001 and 5% in more recent studies. The likelihood of indeterminate or inaccurate pathological findings has decreased from 10% to 4% when comparing clinical studies before and since 2001. Currently a total success rate of greater than 90% is attainable using renal mass biopsy with standard histopathological analysis. Recent studies demonstrated that combining immunohistochemical and molecular analyses may further improve renal mass biopsy accuracy.

Conclusions

Research on expanded analysis of percutaneous renal mass biopsy specimens should remain a top priority. Enhanced renal mass biopsy should not change treatment in most patients with small renal masses, who should be treated with surgical excision. However, future clinical algorithms will likely incorporate enhanced biopsy in situations in which decision making is more challenging.

Key Words: kidney, carcinoma, renal cell, biopsy, epidemiology, molecular, diagnosis

Abbreviations and Acronyms: CT, computerized tomography, F, fluoroscopic x-ray, MRI, magnetic resonance imaging, NA, not available, RCC, renal cell carcinoma, RMB, renal mass biopsy, SRM, small renal mass, US, ultrasound