WILMS-TUMOR - THE PROBLEM OF DIAGNOSTIC-ACCURACY IN CHILDREN UNDERGOING PREOPERATIVE CHEMOTHERAPY WITHOUT HISTOLOGICAL TUMOR VERIFICATION

From 1989 to 1992, 9 consecutive children with a tentative diagnosis o f Wilms tumor underwent therapy planned according to the International Society of Pediatric Oncology (SIOP)-9 Wilms tumor protocol, includin g preoperative chemotherapy. Because tumor biopsy is not recommended i n this SIOP-9 protocol due to a possible tumor spread from open or nee dle biopsy, diagnostic accuracy is mandatory. We present our problems in diagnostic accuracy resulting in withdrawal of 2 children from preo perative chemotherapy, understaging the tumor in 2 and missing exact t umor histology due to complete tumor necrosis in 2. In addition, preop erative chemotherapy was applied in 1 child who later was found to hav e renal cell carcinoma. Although the SIOP-9 protocol of Wilms tumor tr eatment may be effective with regard to reducing the intensity of ther apy, staging problems may be a major drawback in this therapeutic stra tegy based on preoperative chemotherapy.