Unresectable stage IV nephroblastoma: a potential indication for fine-needle aspiration biopsy in children

In the United States, the initial morphologic diagnosis of nephroblastoma is usually determined on a nephrectomy specimen prior to the initiation of any additional therapy. Such an approach, however, is not appropriate in all children; we believe that fine-needle aspiration biopsies (FNAB) should be the initial diagnostic procedure in a minority of patients with suspected Wilms' tumor. One such group of patients is those who present with stage IV disease, especially when it is considered unresectable. Herein we present two children with advanced Wilms' tumor to support our contention. The initial microscopic diagnosis in each was made by FNAB. Following chemotherapy, predominantly necrotic Wilms' tumors were excised. Both patients are alive with no evidence of residual disease or untoward affects from the aspiration procedure.