MR Tumor Staging for Treatment Decision in Case of Wilms Tumor

Nephroblastoma – also known as Wilms tumor – is the most frequent renal malignancy in childhood with the highest incidence of this tumor within the fourth year of life. 80% of patients are less than 5 years old, however it is a rare condition in neonates (<1%). In general, there are no known risk factors for the development of nephroblastoma, but it may be associated with rare conditions like Denys-Drash (triad of congenital nephropathy, Wilms tumor and intersex disorders), WAGR (also called Wilms tumor-aniridia syndrome) and Beckwidth-Wiedeman (giantism associated with tumors and malformations) syndrome. The incidence is approx. 1: 100,000 for western countries including the US, while a lower incidence is reported for Asian countries. If not associated with a syndrome, clinical symptoms – if present at all – are very often unspecific and abdominal pain and palpable tumor can be the only findings at the time of diagnosis. MRI is considered the imaging modality of choice for tumor staging and subsequent treatment planning. If imaging is conclusive, often no biopsy is performed prior to initiation of therapy. Clinical treatment is according to protocols of SIOP (Society of Pediatric Oncology) in MR Tumor Staging for Treatment Decision in Case of Wilms Tumor