Childhood nephroblastoma – How is it diagnosed?

Nephroblastoma (Wilms tumour) is a cancer or mass that arises within the kidney. Usually only one kidney is affected but occasionally both kidneys may be affected at the same time. These children are often  very well and a mass in the abdomen or flank may be picked up incidentally when the child goes to the doctor for another complaint. 

Other symptoms may include abdominal pain, constipation, blood in the urine, and high blood pressure. Tumours that have started to bleed or rupture can cause severe abdominal pain and may require urgent medical attention. 

Diagnostic tests

Once the diagnosis is suspected, an ultrasound or sonar of the abdomen is the first test ordered. This investigation will confirm where the mass or lump in the abdomen is coming from. A CT scan of the abdomen will then confirm the diagnosis. A general anaesthetic may be required dependent on the age of the child. 

Sometimes, if the CT scan is typical of a nephroblastoma, the diagnosis is made on the imaging, and no biopsy is required. However, if there is any doubt about the diagnosis, a biopsy or piece of the tumour is required. This is usually performed under general anaesthetic or sedation. 

A sonar is performed at the time as the biopsy and guides the radiologist to insert a needle directly into the mass without damaging any other structures. A small piece of the mass is removed and sent to a laboratory where it’s examined under a microscope by a pathologist and the diagnosis is then confirmed. 

A chest X-ray or CT scan of the chest is needed to confirm if the cancer has spread to the chest. 

A paediatric oncologist will then start treatment; this requires a combination of surgery, chemotherapy, and possibly radiation therapy.

Header image by Freepik