Bone within bone appearance is seen in?

C i.e. Osteopetrosis In osteopetrosis, there is reduced osteoclastic bone resorption resulting in diffuse symmetrical skeleton sclerosis. Also k/a marble bone disease d/t its stone like quality of bones; however the bones are abnormally brittle & fracture like a piece of chalk. It can present radiologically as? Sclerosis of all bones more prominent at base of skullQ. Sclerosis of veebral end plate 1/t characteristic sandwitch or broad stripped (rugby jersey spine) Q Bone in bone appearanceQ d/t sclerotic foci within the bone.