Single institution experience with Tru-Cut renal mass biopsy for diagnosing Wilms tumor.

PURPOSE To evaluate the efficacy of needle biopsy for diagnosing Wilms tumor (WT) before chemotherapy. MATERIALS AND METHODS We reviewed our institutional experience with Tru-Cut biopsy of pediatric renal masses in patients who subsequently underwent nephrectomy. We compared biopsy pathology with nephrectomy specimens to determine if biopsy accurately predicted final pathology. RESULTS Seven children underwent Tru-Cut renal mass biopsy followed by surgical resection. In 4 patients, the final biopsy pathology was definitively read as WT and in 3 subjects, the pathology was read as WT versus hyperplastic nephrogenic rest. In all 7 patients, the nephrectomy pathology confirmed a diagnosis of WT. There were no complications after biopsy, and no patients have had local or regional recurrence. CONCLUSION In our experience, pre-therapy Tru-Cut biopsy safely provides an adequate specimen for pathologic review in diagnosing WT.