Renal mass biopsy is accurate for small renal masses (4 cm or less), according to a study published in the March issue of The Journal of Urology.
Hwang Gyun Jeon, MD, from the Sungkyunkwan University School of Medicine in Seoul, South Korea, and colleagues evaluated the diagnostic accuracy of renal mass biopsy for small renal masses in a study that included 442 biopsies of renal tumors 4 cm or less. The authors determined biopsy outcomes and concordance rates between renal mass biopsy and final surgical pathology. The initial biopsy was diagnostic in 88.9% of cases and nondiagnostic in 11.1%.
The researchers found that 76% of diagnostic biopsies revealed renal cell carcinoma and 24% were benign. In 90.2 and 31.3% of cases, respectively, renal cell carcinoma histologic subtyping and grading were possible. In 11 of the 49 nondiagnostic cases, a second biopsy was performed; diagnosis was possible in 100% (10 renal cell carcinomas and one oncocytoma). Independent predictors of nondiagnostic biopsy included small tumor size, cystic nature of tumors, and biopsy during the initial years of the study. The rates of accuracy in identifying malignancies, histiotyping, and two-tier grading were 97.1, 95.1, and 68.8%, respectively, between renal mass biopsy and surgical pathology.
“Renal mass biopsy for a small renal mass can be performed accurately,” the authors write. “A second biopsy should be considered in nondiagnostic biopsy cases.”