Bone islands are caused by abnormal accumulation of calcium salts in the normal bones. Bone islands are benign lesions that do not normally become malignant. Some islands grow on the outside of the bone and can irritate the surrounding fatty fascia, causing pain. If this does not work, surgical excision is the only option. Surgical removal is less invasive and usually takes about 7-10 days to recover. The bone island will not recur under normal circumstances.