Bone Tumors

Question 1

Osteoid Osteoma
Definition
Location
Age Range
Path/Imaging
Clinical/Notes

Answer 1

• 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

Question 2

Osteosarcoma
Definition
Location
Age Range
Path/Imaging
Clinical/Notes

Answer 2

• MALIGNANT proliferation of OSTEOBLASTS
  Distal Femur, proximal tibia: knee area, intramedullary, cortical, periosteal
• Teens, Elderly, Bi-modal
• Metz to LG, Imaging&raquo_space; destructive mass with ‘sunburst’ appearance and lifting of periosteum
• Pain, fracture, swelling
• Risk factors: retinoblastoma, Paget dz, radiation exposure

Question 3

Osteochondroma
Definition
Location
Age Range
Path/Imaging
Clinical/Notes

Answer 3

• 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

Question 4

Chondroma
Definition
Location
Path/Imaging
Clinical/Notes

Answer 4

• 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

Question 5

Chondrosarcoma
Definition
Location
Age Range
Path/Imaging
Clinical/Notes

Answer 5

• 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

Question 6

Giant Cell Tumor
Definition
Location
Age Range
Path/Imaging
Clinical/Notes

Answer 6

• 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

Question 7

Ewing Tumor
Definition
Location
Age Range
Path/Imaging
Clinical/Notes

Answer 7

• 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&raquo_space; fusion protein of EWS-FLI-1
• may MIMIC: ALL, metz neuroblastoma, osteomyelitis

Question 8

Fibrous Tumor-Like Conditions
Location
Age Range
Patho/Imaging
Clinical

Answer 8

• Diaphyseal, intramedullary fusiform lesions of long bones
• usu children
• fusiform lesions with “ground glass,” Spindle cells, collagen matrix, woven bone”
• monostotic