Wilms Tumour & Tumours of the Kidney

Wilms tumour, also called nephroblastoma, develops from immature kidney cells that persist after birth. It most often affects children between one and four years of age and usually involves only one kidney, although occasionally both kidneys are affected. Some children with certain genetic conditions or congenital differences have a higher chance of developing Wilms tumour and may be offered regular ultrasound screening.

Other kidney tumours in childhood are much less common. They include clear cell sarcoma of the kidney, rhabdoid tumour, renal cell carcinoma (more often seen in older children and adolescents) and congenital mesoblastic nephroma, a usually benign tumour of very young infants. Because these tumours are managed differently, establishing the exact diagnosis is an important early step.

Most children with a kidney tumour present with a firm, painless swelling of the abdomen, often first noticed by a parent. Other features can include blood in the urine, abdominal pain, fever, poor appetite or high blood pressure. Many children otherwise appear well.

An ultrasound is usually the first test, followed by a CT or MRI scan of the abdomen to define the tumour, check the other kidney and look at the main veins. A CT scan of the chest is performed because the lungs are the most common site of spread. Blood and urine tests assess kidney function and general health.

In Australia, many children with a typical Wilms tumour begin chemotherapy based on the imaging findings, with the diagnosis confirmed when the kidney is removed. A biopsy is sometimes needed when the picture is unusual.

Children with kidney tumours are treated within a multidisciplinary children's cancer service, and the treatment plan is agreed by paediatric oncologists, surgeons, radiation oncologists, radiologists and pathologists together. Treatment for Wilms tumour combines surgery and chemotherapy, with radiotherapy added for some children depending on the stage and the appearance of the tumour under the microscope.

In the approach commonly used in Australia, a short course of chemotherapy is given before surgery to shrink the tumour, making the operation safer and reducing the chance of the tumour rupturing during removal. Surgery then follows, and the pathology results determine the type and length of chemotherapy given afterwards. Your child's surgeon coordinates the timing of the operation with the oncology team so that it fits within this plan.

The standard operation for Wilms tumour is a radical nephrectomy, in which the whole affected kidney, its surrounding fat and the tumour are removed together through an incision across the abdomen. Nearby lymph nodes are sampled at the same time, because their status is an important part of staging. The surgeon also carefully inspects the other kidney and the rest of the abdomen.

When both kidneys are involved, or a child has only one working kidney, a kidney-sparing operation that removes the tumour while preserving as much healthy kidney as possible may be planned. This requires detailed imaging and is discussed carefully with the family beforehand.

The operation is performed under general anaesthesia by a paediatric surgical and anaesthetic team, and children are usually able to live a normal life with one healthy kidney.

Most children stay in hospital for several days after the operation while pain is controlled, bowel function returns and they begin eating and drinking normally. The treating team will advise on wound care, bathing and when your child can return to school and normal play; contact sports are generally avoided for a period after abdominal surgery.

Chemotherapy usually restarts within a few weeks of the operation, guided by the pathology results. Follow-up involves regular clinical reviews, blood pressure checks, kidney function tests and scans of the chest and abdomen, most frequently in the first two years. Because your child will rely on one kidney, the team will also advise on protecting kidney health in the long term, and long-term follow-up clinics monitor for late effects of treatment.