What causes giant cell tumor of bone

Circulating tumor rich, soft and brittle, like granulation tissue, easy bleeding, a fiber-zone and bleeding areas. According to the extent of benign and malignant divided into three degrees: Time: about half of the giant cell tumor of this kind, obviously benign, cytomegalovirus many rare cell division, to the attention of all tumors were for a time before we can judge once tumor. Second: difficult to distinguish between malignant or benign, stromal cells more than once cytomegalovirus less. On three occasions: for obvious vicious, occurred less, mesenchymal cells, nuclei, such as the form of sarcoma, cell division and more. Cytomegalovirus fewer and smaller, less nuclear number one, can be converted into a second three times.