Histological examination images. (A) Section includes lamellae surrounded with congestion of small blood vessels, and blood-filled cystic spaces separated by fibrous septae (HE staining; original magnification, ×40) (B) Multiply of osteoblast proliferation, fibrous connective tissue and multinucleated giant cell proliferation (HE staining; original magnification, ×100). HE, hematoxylin-eosin.