Local staging of Wilms' tumor--computerized tomography correlation with histological findings

The aim of this study was to assess the accuracy of computed tomography (CT) in the local staging of Wilms' tumor.

Twenty-six patients with unilateral, nonmetastatic Wilms' tumors were accrued over the period of 1990 through 1997. Preoperative CT staging was performed before surgical biopsy or excision. The abdominal CT images were reviewed and staged for local disease according to National Wilms' Tumour Study (NWTS) Group Staging V as either intrarenal disease (Stage I), local extrarenal extension amenable to complete local excision (Stage II), or advanced local disease (Stage III). Patients with metastatic (Stage IV) and bilateral disease (Stage V) were excluded from our study. Results were compared to histological findings.

CT scan correctly staged 10 of 26 cases (38%) of Wilms' tumor. CT scan overstaged 12 of 16 (75%) localized renal disease (Stage I) and local extension (Stage II) tumors, and understaged 4 of 10 (40%) localized spread (Stage III) tumors.

CT scan appears to have poor correlation to histological staging. Therefore, basing therapy solely on radiological imaging may lead to some patients receiving more intense therapy than necessary, whereas others do not receive sufficient therapeutic regimens. Histological assessment of the excised mass should remain the standard for staging Wilms' tumors.