Lung tumours are rare in childhood. 75% of lung tumours are malignant. The most common are those which have spread from other organs, such as the kidney or bone. Very occasionally, tumours, similar in type to adult lung cancers, occur. Also, there are some aggressive tumours which develop from embryonic tissue (immature tissue formed during the unborn baby’s development).
Benign tumours affecting children include plasma cell granulomas. They may increase in size as an abnormal response to infection or trauma. Hamartomas, another type of benign growth, contain normal but very disorganised tissue. They can grow very large.