BONE TUMOURS

1. BONE TUMOURS Day : Tuesday Date : 11-12-2007 Time : 1.00-2.00

2. Bone Tumours WHAT SHOULD YOU KNOW • Understand the clinical algorithm • Correlate clinical presentation with radiological features • Understand the classification and types of bone tumours • Comprehend the management of bone tumours • Understand the necessity for a team-approach • Correlate Pathological findings with clinical presentation (Clinico-pathological correlation)

3. BONE TUMOURS • rare but • may result in amputation • disfigurement and great physical challenge

4. Classification of bone tumours Simple classification A i. Primary ii Secondary- more common B i. Benign - oma ii. Malignant - sarcoma

5. Primary Bone tumors are classified according to the cell of origin

7. Diagnosis of Bone Tumours 1. Age of patient 2. Location of tumour 3. Radiological appearance 4. Histological features

8. AGE(probably the most important clinical clue). Age group Most common benign lesions Most common malignant tumors 0-20 non-ossifying fibromafibrous dysplasiasimple bone cystaneurysmal bone cystosteochondroma (exostosis)osteoid osteomaosteoblastomachondroblastomachondromyxoid fibroma eosinophilic granuloma Ewing's sarcomaleukemic involvementmetastatic neuroblastoma osteosarcoma,Ewing's sarcoma, 21 - 40 enchondroma giant cell tumor chondrosarcoma 40 & above osteoma metastatic tumorsmyelomaleukemic involvementchondrosarcomaosteosarcoma (Paget's associated)MFHchordoma

9. SITE OF LONG BONE INVOLVEMENT(most primary bone tumors have favored sites within long bones; this may provide a clue to diagnosis). Diaphyseal lesions centered in the cortex:Osteoid osteoma Diaphyseal intramedullary lesions:Ewing's sarcoma, lymphoma, myeloma. Common for fibrous dysplasia and enchondroma Metaphyseal intramedullary lesions:Osteosarcoma is usually centered in the metaphysis. Chondrosarcoma and fibrosarcoma often present as metaphyseal lesions. Osteoblastoma, enchondroma, fibrous dysplasia, simple bone cyst, and aneurysmal bone cyst are common in this location. Metaphyseal lesions centered in the cortex:Classic location for a non-ossifying fibroma (NOF). Also, a common site for osteoid osteoma. Epiphyseal lesions:Chondroblastoma (Ch) and Giant Cell Tumor (GCT) are almost invariably centered in the epiphysis. Chondroblastoma is a rare tumor seen in children and adolescents with open growth plates. GCT is the most common tumor of epiphyses in skeletally mature individuals with closed growth plates. GCT often shows metaphyseal extension. Metaphyseal exostosis:Osteochondroma

10. Radiological Features

11. Benign Tumours Osteochondroma Also known as an exostosis, is a cartilage –capped out growth. Men are affected three times more often than women Develop in bones of endochondral origin and arise from the metaphysis near the growth plate of long bones especially about the knee

12. Development over time of an osteochondroma beginning with an outgrowth from the epiphyseal cartilage

13. Osteochondroma Clinically present as slow growing masses Can be painful if they impinge on a nerve or if stalk is fractured. In many cases, they are detected as an incidental finding. Rarely they give rise to chondrosarcoma

14. The white arrows point to a mushroom-shaped, peduculated bony excresence arising from the anteromedial aspect of the distal femoral metaphysis, attached to the parent bone and pointing away from the metaphyisis Osteochondroma of femur

15. Osteochondroma

16. Chondroma Benign tumours of hyaline cartilage May arise within the medullary cavity-enchondroma May arise on the surface of bone – subperiosteal chondroma Enchondromas are the most common Located in the metaphyseal region of tubular bones Most enchondromas are asymptomatic and detected as incidental finding

17. Enchondroma of the phalanx with a pathological fracture

18. Enchondroma with a nodule of hyaline cartilage encased by a thin layer of reactive bone.

19. Osteoid osteoma and Osteoblastoma Have identical histology Osteoblastoma larger than osteoid osteoma

20. Osteoid osteoma < 2 cm in greatest dimension Affects teenagers and adolescents 75 % of patients < 25 years Affects cortex of femur or tibia Painful lesion Relieved by salicylate

21. Osteoid osteoma of Femoral neck

22. Osteoid osteoma

23. 1.Compare and contrast: Osteosarcoma Chondrosarcoma Giant cell tumor Ewing's tumor with respect to: Histogenesis age of group affected location in the skeleton histologic hallmarks clinical behaviour prognosis

24. Osteosarcoma (OS) Most common primary malignant tumor of the bone Mesenchymal tumor Cancerous cells produce bone matrix 75 % occur in patients younger than 20 years of age

25. Osteosarcoma (OS) Primary osteosarcoma arise in the metaphysis of long bones of the extremities Secondary osteosarcomas occur in older patients with Paget’s disease More common in men than women Common sites are distal end of femur or proximal tibia

26. Osteosarcoma (OS) Patients with Mutation of Rb gene are predisposed to osteosarcoma Concurrent trauma to bones and joints In the elderly OS often arises from pre existing bone diseases eg: Paget’s disease of bone

27. Osteosarcoma (OS) Clinical Presentation Painful and progressively enlarging masses Spread through blood stream The tumour breaks through the cortex and lifts the periosteum Often metastasizes to the lungs

29. Osteosarcoma on distal end of femur Cortex is destroyed

30. Neoplastic osteoblasts forming osteoid

31. Chondrosarcoma Frequency is about half of osteosarcoma Second most common malignant matrix producing tumor Mean age for chondrosarcoma is 43 years Men are affected more than women

32. Chondrosarcomas Commonly arise in the central portions of the skeleton including Pelvis, proximal femur, ribs, sternum and shoulder girdle

33. Chondrosarcoma Present as painful progressively enlarging masses Prognosis depends on size of tumor Spreads to lungs and skeleton

35. Chondrosarcoma

36. Chondrosarcoma Tumor has developed in the proximal femur Not destroyed the cortex Has a bluish, glassy appearance , reminiscent of cartilage

37. Malignant neoplastic cells produce a chondroid matrix

39. The aggressiveness of chondrosarcomas can be predicted by their histologic grade. Grading system is based on three parameters: cellularity, degree of nuclear atypia and mitotic activity. Grade 1 (low-grade)Very similar to enchondroma. However, the cellularity is higher, and there is mild cellular pleomorphism. The nuclei are small but often show open chromatin pattern and small nucleoli. Binucleated cells are frequent. Mitoses are very rare. Grade 1 chondrosarcomas are locally aggressive and prone to recurrences, but usually do not metastasize. Grade 2 (low-grade)The cellularity is higher than in Grade 1 tumors. Characteristic findings are moderate cellular pleomorphism, plump nuclei, frequent bi-nucleated cells, and occasional bizarre cells. Mitoses are rare. Foci of myxoid change may be seen. Unlike Grade 1 tumors, about 10% to 15% of Grade 2 chondrosarcomas produce metastases. Grade 3 (high-grade)Characteristic findings are high cellularity, marked cellular pleomorphism, high N/C ratio, many bizarre cells and frequent mitoses (more than 1 per hpf). These are high grade tumors with significant metastatic potential.

40. Giant cell tumour of bone(GCT) Contains a profusion of multinucleated osteoclast type giant cells Relatively uncommon benign But locally aggressive Usually arises during 5th decade Slight female predominance

41. Giant cell tumour of bone(GCT) Involve both epiphysis and metaphysis In adolescents limited to metaphysis Common sites are distal femur and proximal tibia

46. Ewing sarcoma(ES) Primary malignant small round cell tumour Ewing sarcoma has the youngest average age at presentations (10-15 years) Boys slightly more often affected than girls

47. Ewing sarcoma(ES) Pelvis is the most common site usually arises in the diaphysis of long bones especially femur followed by tibia and humerus

48. Ewing sarcoma of tibia from a child

50. The following studies are required to support the diagnosis of ES and PNET: • Demonstration of t(11;22) or EWS-FLI-1 fusion transcript (present in both ES and PNET) Immunostains(both ES and PNET are positive for CD99/O13. In addition, PNET shows positive staining with neural markers)EM (ES cells are undifferentiated and show prominent glycogen deposits; PNET shows neural differentiation)