Bone forming tumours

Tumor	Age	Location	Clinical presentation	Pathology	Radiology	Treatment	Prognosis	DD
Osteoid osteoma	5-25yrs, M:F-2:1	Any endochondral bone,tibia & femur- 50%. spine - post elements	Pain worse at night relieved by aspirin. 10% spine -> scoliosis. joint effusion, LLD, synovitis self limiting. surgery for pain relief Pain decreases as it matures lasting 18 - 30 months . healed by 3 - 7 years	Nidus < style="text-decoration: underline;">osteoblastic tissue surrounded by vascular fibrous tissue finally surrounded by mature reactive cortical bone. Contains fibroblasts, osteoblasts and osteoclasts, no marrow element. calcified centre in nidus	Lytic nidus surrounded by sclerotic bone (which may mask the nidus) Centre of nidus may be calcified CT or tomograms -> diagnosis Hot spot on bone scan	NSAIDs/ Nidus excision with intact rim of reactive bone.Intraop localisation with Bone scan/Tetracycline/ CT/ X-Ray .( dumbbell nidus)./Percut radiofrequency coagulation
Osteoblastoma	10 - 35 yrs	spine (post elements), / long bones or phalanges	Less intense pain than osteoid osteoma. often with scoliosis	More organised &larger size (2 - 10 cm) Less reactive bone.. Vascular stroma, abundant irregular areas of mineralised bone and osteoid. Vascular tumour +/- haemorrhage and +/- calcification. Texture gritty and friable.Spectrum of aggressiveness	Well demarcated osteolytic lesion sometimes containing flecks of calcification.May be aggressive.metaphyseal/ enlarges bone. periosteum intact. no soft tissue mass. Bone scan - intense activity	Intra capsular resection -> 20% recurrence En bloc resection -> no recurrence Use cryotherapy (PMMA) as adjuvant		ABC osteoid osteoma (spine) Giant cell tumour Osteosarcoma (if more aggressive)
Osteosarcomas	10 - 20 & 50 - 70 yrs, M>F	distal femur or around the knee. metaphyseal	Pain-constant and worse at night. Pathological fracture rare. tender lump which may lack a definite edge and may be attached to muscle may pulsate and feel warm. Telangiectatic-osteolytic-path # of femur tibis diaphysis.	Pleomorphic and anaplastic cells ,abundant fibrous and chondroid matrix. Stroma of spindle cells with numerous mitoses. high grade aggressive tumours. 50% osteoblastic, 25% chondroid, 25% fibroblastic. 20% are secondary (eg Pagets, enchondromas, osteochondromas, chronic osteomyelitis, irradiation, fibrous dysplasia, osteopetrosis, 100% of bilateral retinoblastomas and bone infarction). In the metaphysis, initially extends within medulla, perforates the cortex, raise periosteum -> Codman's triangle.As the tumour mass expands new bone forms along vascular channels -> appearance of sunray spicules. Mets via blood to lung , bones. oncogenes - Retinoblastoma gene and P53	Variable with combination of bone destruction and bone formation. Sun ray spicules (Radial ossification) and Codmans triangle (lifting of periosteum).Cortical breach common. Adjacent soft tissue mass.Joint space rarely involved.25% Lytic, 35% Sclerotic, 40% Mixed	primary by en bloc excision and microscopic disease by chemotherapy (Methotrexate -> 80% response).T10 regimen (methotrexate, vincristine, adriamycin). for 12 months. Radiotherapy- local pain /surgically inaccessible lesions / painful mets. Relatively radio-resistant, pre-operatively to decrease the size and vascularity. Sx- Wide resection / Amputation. Reconstruction -Allografts/Endoprosthesis/ expendable bone (fibula, ilium)/ Rotationplasty	Untreated -> 95% death in 2 years.10% have macro-metastases at presentation; 90% have micro-metastases.metastatic (Stage 3) disease 5 year survival now 30 - 40% (10-20% with surgery alone). adults /big/secondary tumor/proximal/telangiectatic/high grade is bad. Parosteal / Intra osseous (classical) osteosarcoma -> good prognosis.Pathological fracture does not affect prognosis	callus / myositis ossificans Stress fracture Osteomyelitis or syphilis Benign bone tumour Ewings
Parosteal Osteosarcoma	30 - 50 yrs. F>M	posterior aspect of distal femur, juxtametaphyseal	constant ache or lump		Well circumscribed mass.May be separated from cortex by a lucent line (30%).Broad based tumour with mottled calcification. Cortex not eroded Does not invade medullary cavity . Tends to encircle bone	Chemotherapy or radiotherapy not effective in preventing recurrence -> wide surgical resection	better than classical osteosarcoma. 70-80% 5 year survival.not different in relation to stage at presentation	Osteochondroma Myositis ossificans