Does Wilms tumour cause abdominal swelling?

Wilms tumour is a kidney tumour that mainly affects children. As the mass grows in the abdomen, it can make the tummy look or feel enlarged. A child may also have a firm lump, discomfort, fever, blood in the urine, reduced appetite, nausea, or changes in energy. Abdominal swelling alone cannot identify its cause, and many non-cancer conditions can produce a similar appearance.

Avoid pressing or repeatedly examining a suspected abdominal mass. A clinician may examine the child gently and arrange imaging and urine or blood tests. If Wilms tumour is considered, specialist assessment is needed to understand the kidneys and the rest of the abdomen.

Arrange a medical assessment for persistent or unexplained abdominal enlargement, especially when it is accompanied by a firm lump, pain, fever, blood in the urine, poor appetite, or unusual tiredness. Note when the swelling began, whether it changes, and any urinary or bowel symptoms. Do not give new medicines for ongoing symptoms without advice from a clinician, and do not massage a lump.

Get urgent help if the child has severe abdominal pain, repeated vomiting, trouble breathing, fainting, marked weakness, heavy blood in the urine, or a rapidly enlarging abdomen. Sudden deterioration needs emergency assessment. Keep the child comfortable and avoid pressure over the abdomen while arranging care.

What could be causing the swelling, and which examination or scan is needed? Should we avoid contact sports or pressure on the abdomen until the cause is clear? Which changes should lead us to seek same-day care?