Evaluation of Sonographically Guided Percutaneous Core Biopsy of Renal Masses

Abstract

All biopsies provided sufficient material for analysis. Biopsy findings were positive for malignancy in 19 (73%) of 26 masses. Histologic diagnoses included renal cell carcinoma were (n = 11), metastasis (n = 3), lymphoma (n = 2), and transitional cell carcinoma (n = 2). Specific cell type characterization could not be made on one biopsy, but the specimens were highly suspicious for malignancy. Biopsy revealed seven (27%) of 26 benign diagnoses: oncocytoma (n = 3), angiomyolipoma (n = 2), and fibrosis (n = 2). The average follow-up period for patients with benign diagnoses was 10 months. One case of surgically proven necrotic pyelonephritis was mischaracterized as fibrosis at core biopsy. Sonographically guided percutaneous core biopsy of renal masses showed a sensitivity of 100% and a specificity of 100% for the diagnosis of malignancy. The core specimens yielded a specific diagnosis in 92% (24/26) of masses. No immediate complications occurred after the procedure. One patient developed a pseudoaneurysm that presented 3 months after the biopsy. CONCLUSION. Sonographically guided percutaneous core biopsy is a reliable and accurate method for evaluating renal masses.