SAN DIEGO, CA USA (UroToday.com) - Use of percutaneous renal biopsy (PRB) is on the rise and many have incorporated this diagnostic tool into their evaluation and staging algorithm. Although impact on patient management may be significant, limitations of renal biopsy must be recognized.
Dr. Sameer Deshmukh and colleagues presented their evaluation of a large, single-institution series of 1 000 PRBs from the Massachusetts General Hospital. Tumor size distribution in their cohort was as follows: 80% 0-4 cm, 16% 4-7 cm and 4% > 7 cm. The majority of the tumors (82%) were solid, with cystic lesions comprising 18%. Ninety-two percent of biopsies took place under CT guidance and 99% had core needle biopsies -- with 94% having both core and FNA specimens. Twenty-two percent of the biopsies were considered non-diagnostic, with a much higher rate in cystic (63%) vs solid (13%) lesions. Interestingly, tumor subtype and grade were reported in only 80% and 35% of specimens, respectively. For lesions undergoing extirpation, 97% concordance of PRB with surgical pathology was observed, with 92% concordance for subtype and 76% for tumor grade. Biopsies that were initially non-diagnostic and underwent a repeat biopsy (N=55) remained non-diagnostic on the repeat biopsy 58% of the time, with most ultimately proving to be malignant on final resection (91%).
The authors concluded that masses < 2cm and cystic lesions were more likely to result in non-diagnostic biopsy as compared to larger and solid lesions, thus recommending against PRB in masses < 2 cm and cystic lesions, unless performed at time of ablation. Caution should be exercised when interpreting single-institution biopsy data, as significant variations across interventional radiology, diagnostic radiology, and pathology departments exist.
Presented by Sameer M. Deshmukh, Manish Dhyani, Francis J. McGovern, W. Scott McDougal, Aria F. Olumi, Douglas M. Dahl, Ron Arellano, Anthony Samir, Michael L. Blute, and Adam S. Feldman at the American Urological Association (AUA) Annual Meeting - May 4 - 8, 2013 - San Diego Convention Center - San Diego, California USA
Reported for UroToday.com by Serge Ginzburg, MD
