How common is new lump or swelling in childhood cancer?

In a child with cancer, a lump may be related to the area where a tumour is growing or to enlarged lymph nodes nearby. Swelling can also occur in soft tissue, bone, the abdomen, or another body region, depending on the cancer type. The lump may be painless, tender, firm, or mobile, and its appearance alone cannot identify the cause. Infection, a cyst, an injury, or a normal variation can also produce a lump. The useful clues are where it is, when it appeared, whether it is changing, and whether other symptoms accompany it.

Note the date you first noticed the change and measure or photograph it only if this can be done comfortably and privately. Record pain, redness, warmth, fever, recent injury, weight or appetite changes, tiredness, night sweats, and any change in movement or bowel habits. Arrange an assessment with the child’s clinician, especially when the lump persists, grows, returns, or has no clear explanation. The clinician may examine the area and decide whether observation, imaging, blood tests, or another evaluation is appropriate.

Seek urgent medical help if swelling is rapidly increasing, severe pain develops, the child has trouble breathing or swallowing, the abdomen becomes markedly distended, or the child appears very unwell. Prompt assessment is also appropriate for a lump with persistent fever, unusual bruising or bleeding, significant weakness, or a new difficulty using an arm or leg. These signs do not establish cancer; they indicate that the child needs timely examination.

Ask what findings make the lump more concerning, how long it is reasonable to observe it, and which changes should trigger an earlier review. You can also ask whether the location suggests a lymph node, soft-tissue change, bone problem, or another cause; whether imaging is needed; and how your child should manage pain while waiting for assessment. Bring a timeline of changes and a list of medicines or recent illnesses.