A. Natural history

B.  Staging criteria

C.  Bone lesions

   1.  Cartilaginous
       a.  Enchondroma
           i.  Ollier disease
           ii. Maffucci syndrome   
       b.  Chondromyxoid fibroma 
       c.  Chondroblastoma 
       d.  Osteochondroma 
           i.  Hereditary multiple exostoses 
       e.  Juxtacortical (periosteal) chondroma 
       f.  Chondrosarcoma   
           i.  Primary 
           ii.  Secondary 
           iii.  Clear cell 
           iiii.  Dedifferentiated

   2.  Osseous 
       a.  Osteoma 
       b.  Osteoid osteoma
       c.  Osteoblastoma 
       d.  Osteosarcoma 
           i.  Parosteal Osteosarcoma   
           ii.  Periosteal Osteosarcoma
           iii.  Telangiectatic Osteosarcoma

   3.  Fibrous and fibrohistiocytic  
       a.  Fibroxanthoma (nonossifying fibroma) 
       b.  Fibrous dyplasia  
           i.  McCune - Albright syndrome 
       c.  Fibrosarcoma 
       d.  Malignant fibrous histiocytoma

   4.  Vascular 
       a.  Hemangioma 
       b.  Angiosarcoma

   5.  Miscellaneous 
       a.  Simple (unicameral) bone cyst
       b.  Langerhans cell hisitiocytosis (histiocytosis X)  
       c.  Giant cell tumor
       d.  Aneurysmal bone cyst 
       e.  Adamantinoma
       f.  Ewing sarcoma
       g.  Chordoma 
       h.  Multiple myeloma/plasmacytoma 
       i.  Leukemia 
       j.  Lymphoma 
           i.  Hodgkin 
           ii.  Non-Hodgkin 
       k.  Metastasis