1. The document discusses the classification, diagnosis, and imaging appearances of various bone tumors and tumor-like lesions. 2. Key bone tumors discussed include osteosarcoma, giant cell tumor, and bone cyst. Osteosarcoma is classified based on X-ray signs into osteosclerotic, osteolytic, or mixed types. 3. Imaging findings help determine if a bone lesion is benign or malignant based on characteristics such as boundaries, destruction pattern, periosteal reaction, and surrounding soft tissues.

1. Bone Tumor & Tumor-like lesions Sun Yat-sen Memorial Hospital SYSU

5. 2. Classification of Bone Tumor Tumor-like lesion Bone cyst, Fibrous dysplasia Primary Bone Tumor Tumor from Bone Tissue benign Osteochondroma, Giant cell tumor, Osteoma, Chondroma, Chondroblastoma malignant Osteosarcoma, Chondrosarcoma, Fibrosarcoma Tumor from Bone Affiliated Tissue benign Osteoangioma, Odontogenic tumor (exp. Adamantinoma) malignant Ewing's sarcoma, Reticulum cell sarcoma of bone, Notochordoma, Myeloma Metastatic Tumor Carcinoma, Sarcoma, Neuroblastoma Carcinoma, Sarcoma, Neuroblastoma

6. WHO Classification of Bone Tumor & Tumor like lesions （ 2002 ） 1 ． Cartilaginous tumor 2 ． Osteogenic tumor 3 ． Fibrogenic tumor 4 ． Fibrohistiocytic tumor 5 ． Ewing sarcoma/Primitive neuroectodermal tumor 6 ． Blood-cell forming tissue tumor 7 ． Giant cell tumor 8 ． Notochord tumor 9 ． Vascular tumors 10 ． Myogenic tumor 11 ． Lipogenic tumor 12 ． Neural tumor 13 ． Confounding tumor 14 ． Other tumor 15 ． Arthropathy synovial chondromatosis 16 ． Bone and soft tissue tumor related c ongenital or hereditary syndrome

10. 3, Steps of Diagnostic Analysis---clinical data

18. Differential diagnosis between Benign and Malignant Bone Tumor items Benign Malignant growth Slow, compressing neightbouring tissue, no metastasis Quick, neightbouring tissue invading, metastasis Signs of the Lesion Expansive, well-defined, thin but continue tissue Invading, ill-defined, irregular destruction of cortex, tumor bone formation Periosteal reaction most of time (-), can be shown after pathological fracture, but no bony destruction Different forms of periosteal reaction, can be destructed by the tumor Surrounding soft tissue No mass, well-defined if there is Mass formation, indistinct demarcation with surrounding tissue

23. Osteosarcoma in superior part of tibia ( Osteosclerotic type, ivory tumor bone), obvious tumor bone formation which invading into soft tissue Osteosclerotic Osteosarcoma

25. Cotton like tumor bone, Codman’ triangle Osteosclerotic Osteosarcoma in Fibula

26. Osteosclerotic o steosarcoma in inferior femur, obvious tumor bone formation ( ) and big mass in soft tissue (M) , cortex destruction and become thinner ( ) Osteosclerotic Osteosarcoma M M

28. Osteolytic o steosarcoma in distal metaphysis of the femur, apparent Osteolytic destruction is seen, associated with soft tissue mass and Codman’ triangle ( ) Osteolytic Osteosarcoma

29. Osteosarcoma Osteolytic destruction in sup erior tebia, soft tissue mass formation, with Codman’ triangle ( )

32. Osteosarcoma in superior tibia, obvious bone destruction and tumor bone formation, periosteum proliferation. Codman’ triangle ( ) Mixed Osteosarcoma

33. Mixed Osteosarcoma

37. Giant cell tumor of fibular

38. Giant cell tumor of radius Expansive bone destruction in the distal end of L-radius, reach to the subchondral region of the joint but the bone surface is still intact, multilocular, well-defined, no sclerosis, no calcification or ossification inside

39. Giant cell tumor Expansive bone destruction in distal end of R-radius ( ), with in complete bone shell, soft tissue formation extend outside the bone shell.

42. (A) Bone cyst of R- Humerus , develop longitudinally, slight expansive: (B) Complicate with pathologic fracture; (C): Recheck after fracture, density increase inside the cyst. A B C

43. Bone cyst of femur Radiolucent, develop longitudinally, well-defined margin, no sclerosis. CT show uniform low density inside the cyst.

46. Osteolytic Bone Metastases Nasopharyngeal Carcinoma patient, osteolytic bone destruction in R- humerus and clavicle, unclear margin, no ossification or calcification. Clavicle mass formation （ M ） M

47. Osteolytic Bone Metastases Round destruction area in cranial bones, ill-defined margin, no sclerosis

48. Bone Metastases

49. Prostatic carcinoma. Increase density in pelvis, lumbosacral vertebrae and bilateral femur . Osteoblstic Bone Metastases

50. Uniform increased density of L 2 , L 4 , L 5 vertebra, sacral vertebrae and iliac bone. Osteoblstic Bone Metastases

51. Mixed Bone Metastases Small and large patchy bone destruction area as well as increased density area in pelvis, lumbosacral vertebrae and bilateral femur.