Role of percutaneous needle core biopsy in diagnosis and clinical management of renal masses.

Percutaneous needle core biopsies are routinely performed for renal mass diagnosis in some institutions. Because of limited tissue availability, accurate diagnosis can be challenging, and the role of needle core biopsy (NCB) remains debatable in kidney tumor management. In the present study, we reported our experience in diagnosing renal masses via percutaneous NCB and the role it plays in clinical management of these masses. We studied 301 consecutive cases of percutaneous NCBs performed for 280 renal masses from 269 patients between year 2008 and 2011 by reviewing final pathology diagnosis, hematoxylin and eosin slides, and ancillary studies. Diagnostic accuracy was determined by comparing biopsy and nephrectomy diagnoses in a subset of renal masses. Clinical data including demographic information, clinical presentation, radiographic findings, and treatment information were reviewed subsequently if available. The size of renal masses in our study cohort ranged from 0.5 to 24 cm, and 78% of them were small renal masses. Definite diagnoses were rendered in 89% of the renal masses by NCBs, and 23% of them were benign. Renal mass NCB was 100% accurate in diagnosing primary renal malignancy and 93% accurate in determining histologic subtypes. Clinical management was analyzed for 180 renal masses. There was significant difference in clinical management between different diagnostic groups. We conclude that percutaneous NCB is a powerful tool not only for definite tissue diagnosis of renal masses before treatment but also plays an important role in guiding patient management and obtaining material for future molecular studies for targeted therapies.