Bone tumors Flashcards
What are the risk factors for osteoid osteoma?
Young adults, males
Where are the most common sites for osteoid osteomas?
Appendicular skeleton; diaphysis and metaphysis of distal humerus, digits of the hand, femur, tibia
What are the three primary characteristics of osteoid osteomas?
Small size, self-limiting growth, tendency to cause extensive reactive changes in adjacent tissues
What size are osteoid osteomas?
Usually 1cm or less
What are the radiological features of osteoid osteomas?
Nidus with sclerotic reaction, cortical thickening
What are the histological features of osteoid osteomas?
Irregular bone trabeculae lined by benign osteoblasts, fibrovascular stroma, occasional osteoclasts, sclerotic surrounding bone
What is the typical clinical presentation of osteoid osteoma?
Nocturnal pain alleviated by NSAIDs
What is the typical clinical presentation of osteoblastoma?
Dull/achy pain, may be relieved by NSAIDs
What are the risk factors for osteoblastoma?
Young adults, male
What are the most common sites for osteoblastoma?
Axial/spine, diaphysis and metaphysis of lower extremity
What are the risk factors for osteosarcoma?
Children/young adults, elderly, Paget disease, familial retinoblastoma, LiFraumeni syndrome (germline p53 mutation)
Is osteoid osteoma benign or malignant?
Benign
Is osteoblastoma benign or malignant?
Benign
What are the radiological findings of osteoblastoma?
Lytic with or without sclerotic margin; internal calcification and ossification; lacks surrounding bone sclerosis
What are the histological findings of osteoblastoma?
Similar to osteoid osteoma without surrounding bone sclerosis; irregular bone trabeculae lined by benign osteoblasts, associated fibrovascular stroma and occasional osteoclasts
Is osteosarcoma benign or malignant?
Malignant
Where are tumors usually located in osteosarcoma?
Metaphysial (long bones) in youth, often distal femur or proximal tibia; axial skeleton/flat bones in older adults
What are the typical radiological findings in osteosarcoma?
Lytic and/or sclerotic appearance; Codman triangle (elevation of periosteum) or sunburst pattern
What are the typical histological findings in osteosarcoma?
Atypical malignant cells producing osteoid of mineralized neoplastic bone, usually accompanied by mitotic activity and necrosis, host bone permeation
What are the two genes that are often involved in low grade osteosarcoma?
CDK4 and MDM2
What are the risk factors for osteochondroma?
Young adults, male
Is osteochondroma benign or malignant?
Benign
Where are tumors usually found in osteochondroma?
Usually metaphysis of long bones that undergo endochondral ossification
What genes are often involved in osteochondroma?
EXT1 and EXT2
What are the typical radiological features of osteochondroma?
Bony exostosis with cartilaginous cap (First Aid); pedunculated or sessile ossified stalk in communication with underlying bone that grows away from adjacent joint (lecture)
What are the typical histological findings of osteochondroma?
Hyaline cartilage cap undergoing endochondral ossification to bone with normal marrow
Where in the body are tumors usually found in enchondroma?
Appendicular skeleton, usually hands and feet
What are the typical radiological findings in enchondroma?
Circumcised lytic lesions, usually with punctate and ring-like calcifications
What are the typical histological findings in enchondroma?
Nodular growth of hyaline cartilage in medullary region or surface of bone
What genes are often involved in enchondroma?
IDH1 and IDH2
What are the risk factors for chondrosarcoma?
Older adults
Where in the body are tumors usually found in chondrosarcoma?
Axial skeleton; pelvis, humerus, proximal femur
What are the typical radiological findings in chondrosarcoma?
Lytic, destructive lesion usually with punctate and ring-like calcification
Is chondrosarcoma benign or malignant?
Malignant
Is enchondroma benign or malignant?
Benign; may progress to chondrosarcoma
What are the typical histological findings in chondrosarcoma?
Bone invasion and entrapment with possible necrosis; abnormal matrix-producing cartilage
What are the risk factors for giant cell tumor of bone?
Age 20-40 years, skeletally mature
Are giant cell tumors benign or malignant?
Benign; locally aggressive
What are the typical radiological findings in giant cell tumors?
Lytic lesion involving epiphysis; soap bubble-like appearance
Where are giant cell tumors usually found?
Epiphysis of long bones, usually distal femur and proximal tibia
What are the typical histologic findings in giant cell tumors?
Sheets of osteoclastic giant cells with numerous nuclei
What are the risk factors for Ewing sarcoma?
Age <20, male
Where are tumors usually found in Ewing sarcoma?
Diaphysis of long bones; pelvis, scapula, ribs
What is the genetic mutation associated with Ewing sarcoma?
t(11;22) causing EWSR1-FLI1 fusion gene
What are the typical radiologic features of Ewing sarcoma?
Destructive and permeative tumor, usually in diaphysis, often soft tissue extension; onion skin periosteal reaction
What are the typical histological findings in Ewing sarcoma?
Anaplastic small “blue cells” (small, round, little cytoplasm, fairly uniform in size and shape), possible necrosis
