Wilms tumour

Abstract Wilms tumour (nephroblastoma) arises from the primitive metanephric blastema and is the most common renal malignancy in childhood. Although in the vast majority of cases, Wilms tumour occurs sporadically, it may be associated with syndromes shown to have specific genetic defects. Typically, children present with an incidentally discovered abdominal mass. In the UK, a biopsy is usually performed by ultrasound-guided coaxial needle core biopsy to confirm the diagnosis. The differential diagnosis includes mesoblastic nephroma, angiomyolipoma, nephroblastomatosis, cystic nephroma, rhabdoid tumour, clear cell sarcoma, renal cell carcinoma, intrarenal lymphoma, and neuroblastoma. Staging is vital as Wilms tumour is managed in a multidisciplinary manner involving chemotherapy, surgery, and radiotherapy, depending on the stage of the disease. Bilateral disease and venous extension require careful preoperative planning.