Benign tumours

Many of the benign tumours appear to have been present from birth and to grow with the child. They may be multiple, suggesting a problem in development, and if they are truly benign they stop growing when the child stops growing.

Osteochondromas are outgrowths of the bone, which may look much smaller on X-ray than they feel on clinical examination. This is because the outgrowth of bone has a large cartilage cap over it. Growths within the bones such as enchondromas may weaken the bone so that it fractures. The benign tumour is then diagnosed on X-ray with a pathological fracture running across it (Fig. 25.1).

Where possible, benign tumours should be left alone. There are, however, three indications for surgical intervention in a benign tumour (Table 25.2).

1. If there is doubt about diagnosis and a biopsy is needed to determine whether the tumour is, indeed, benign or malignant. In this case surgery should be planned as if the tumour is malignant, and an approach made which allows either complete excision of the tumour or an incision which will not interfere with further surgery later, if a massive implant or amputation is required.

2. If the bone is so weakened that a pathological fracture has occurred or is likely to occur. In this case the contents of the tumour can be curetted out and the cavity filled with chips of bone harvested from elsewhere in the patient.

3. If the bony protuberance is so prominent that it creates a cosmetic deformity or interferes with muscles or joints, so that the limb cannot function normally.