[Renal tumors in children and adolescents]

Diagnosis and therapy of renal tumors in children and adolescents are standardized by study protocols from major international societies. Imaging plays a central role, and in Europe patients between the ages of 6 months and 14 years with renal tumors are referred to neoadjuvant chemotherapy without histological confirmation according to the study protocol due to the frequency of Wilms tumor.

Ultrasound is used worldwide as the primary investigative procedure for suspected renal tumors. In Europe, magnetic resonance imaging (MRI) has become established for more advanced diagnosis. In addition to differential diagnosis, staging is crucial for therapy. According to current protocol, this includes computed tomography (CT) of the thorax for the evaluation of pulmonary metastases.

Diffusion-weighted MRI provides promising results for the differentiation of nephroblastoma subtypes in addition to improved detectability of tumor foci. However, sufficient evidence is lacking.

Differentiation of Wilms tumor from the highly malignant non-Wilm tumors, such as malignant rhabdoid tumor and clear cell sarcoma of the kidney, remains inconclusive based on imaging alone. Differential diagnosis is, therefore, based on morphologic and epidemiologic criteria.

The high degree of standardization in the diagnosis and treatment of renal tumors in children and adolescents has led to a significant improvement in prognosis. Overall survival of patients with Wilms tumor is currently over 90%.