michael68,
A "Bone Island" is an enostosis. This is a small focus of hard cortical bone within the spongy cancellous bone, of a bone within the body. It is a benign finding. Bone islands do not cause any symptoms. If a bone island is suspected of causing symptoms, it should be evaluated, as some other process is going on.
However, "bone islands" do not occur in lung tissue. They can occur on the ribs. But, it is possible to have areas of calcification within the lung tissue.
There are many causes of calcifications within the lung tissue. It is known that lung nodules with calcification are usually benign.
You should discuss this finding with your physician.
Good luck.