Hello. Kindly check the whole body of your child as a problem with bone may be in other parts of body as well plus if he is not experiencing pain doesn't mean there is no problem. You should visit a doctor if the bulge or swelling is hard and it can't be moved under the skin with your hand. Also look for any decreased eyesight in recent days. X Ray spine is mandatory in these situations. And MRI of spine will be extremely helpful( do mri if swelling is increasing in size). Hope that answer the question. Thanks