1
Q
Osteoid Osteoma Definition Location Age Range Path/Imaging Clinical/Notes
A
- Benign tumor of OSTEOBLASTS (that produce osteoid) surrounded by a RIM of reactive bone
- Diaphysis, Cortex of long bones (femur), < 2 cm
- teens and < 25 y/o
- diaphyseal cortical with sclerotic thickening around a small lucent (osteoid/osteoblast) tumor
- Bone pain that resolves with ASPIRIN
2
Q
Osteosarcoma Definition Location Age Range Path/Imaging Clinical/Notes
A
- MALIGNANT proliferation of OSTEOBLASTS
Distal Femur, proximal tibia: knee area, intramedullary, cortical, periosteal - Teens, Elderly, Bi-modal
- Metz to LG, Imaging»_space; destructive mass with ‘sunburst’ appearance and lifting of periosteum
- Pain, fracture, swelling
- Risk factors: retinoblastoma, Paget dz, radiation exposure
3
Q
Osteochondroma Definition Location Age Range Path/Imaging Clinical/Notes
A
- Cartilage-bone, Most common bone tumor
- meta-diaphyseal
- Teens
- arises from lateral projection of growth plate (meta-diaphysis), bone is contiguous with marrow space
- may progress to chondrosarcoma
4
Q
Chondroma Definition Location Path/Imaging Clinical/Notes
A
- benign tumor of cartilage
- medulla of SMALL BONES of HANDS AND FEET
- lytic with speckled calcification
- Ollier’s: multiple chondromas with fibrous dysplasia
- Mafucci’s: multiple chondromas with angiomata
5
Q
Chondrosarcoma Definition Location Age Range Path/Imaging Clinical/Notes
A
- malignant tumor of cartilage
- Medulla of PELVIS or CENTRAL SKELETON
may also be peripheral - > 50 y/O
- Histology may be low grade or high grade
- slowly enlarging mass
6
Q
Giant Cell Tumor Definition Location Age Range Path/Imaging Clinical/Notes
A
- benign, but aggressive, tumor of giant cells and stromal cells
- Metaphyseal, May extend to epiphysis Often knee
- 20-40 y/o
- lytic lesion appearing after closure of growth plates: “soap bubble” appearance
- pain, fracture, high recurrence
7
Q
Ewing Tumor Definition Location Age Range Path/Imaging Clinical/Notes
A
- malignant proliferation of poorly-differentiated cells derived from NEUROECTODERM and mononuclear cells * diaphysis of long bones
- 5-15 y/o
- onion skin appearance on Xray, Biopsy: small round blue cells that look like lymphocytes, but are glycogen-rich
11;22 translocation»_space; fusion protein of EWS-FLI-1 - may MIMIC: ALL, metz neuroblastoma, osteomyelitis
8
Q
Fibrous Tumor-Like Conditions Location Age Range Patho/Imaging Clinical
A
- Diaphyseal, intramedullary fusiform lesions of long bones
- usu children
- fusiform lesions with “ground glass,” Spindle cells, collagen matrix, woven bone”
- monostotic
