Renal cell carcinoma in children: A rare differential diagnosis of Wilms' tumor

Renal cell carcinoma is a rare tumor in childhood, however, rare tumors must be kept in mind if tumor therapy protocols like the SIOP-9 or SIOP 93-01 Wilms' tumor trial include preoperative chemotherapy based on clinical and radiologic findings without further histologic tumor confirmation. We present a 12-year-old boy initially believed to have a stage IV Wilms' tumor with pulmonary metastasis. Following chemotherapy with doxorubicin, vincristine, and actinomycin D, subsequent tumor nephrectomy revealed a highly differentiated renal cell carcinoma (pT2pN0). Wedge resection of the lung showed no evidence of a pulmonary metastasis (M0). The benefit of preoperative chemotherapy with regard to downstaging of the tumor must be considered carefully, taking into account the risk of incorrect tumor diagnosis.