Bone cancer Flashcards
What are 3 histological patterns of bone destruction?
- Geographic: lesion has a clearly defined margin
- Moth-eaten: larger holes of various sizes
- Permeative: ill-defined, diffuse, subtle appearance
What is the term for a small benign bone tumour usually seen in male children/adolescents?
Osteoid osteoma
Where do osteoid osteomas usually form?
Midshaft of femur
What is the cell lineage of an osteoid osteoma?
Mesoderm > Fibroblasts > Osteoblasts > Osteoid osteoma
What is the most common symtom of an osteoid osteoma?
Localized, increasing, severe pain in the lower leg
How does an osteoid osteoma appear on CT scan?
Tumour core (nidus): osteoid tissue containing osteoblasts, osteoclasts, granulation tissue, nest-like appearance
Shell of dense, reactive, new bone
What is the prognosis of osteoid osteoma?
Excellent: cannot become malignant
What is the term for a highly malignant tumour of osteoblasts and neoplastic bone?
Osteosarcoma
How common is osteosarcoma?
Most common type of malignant primary bone tumour
(which is still rare, because primary bone tumours are rare)
What demographics are commonly affected by osteosarcoma?
Males
Young people (10-25 yrs)
Old people (>60 yrs)
What comorbidity may predispose an individual to osteosarcoma?
Paget’s disease
What are 3 common places where osteosarcoma may be found?
- Knee
- Vertebrae
- Pelvis
Why does osteosarcoma increase a patient’s risk for fracture?
Tumour destroys bone cortex
What is the cell lineage of an osteosarcoma?
Mesoderm > Fibroblasts > Osteoblasts > Osteosarcoma
What is the histological appearance of an osteosarcoma?
Pleomorphic cells mixed with new bone
What is the term for a commonly benign tumour of giant osteoclasts causing extensive bone resorption?
Giant cell tumour (osteoclastoma)
What demographics are commonly affected by giant cell tumour?
Adults (20-40 yrs)
Older women (especially those with Paget’s, radiation exposure)
Where does giant cell tumour usually occur?
Usually at junction of metaphysis & epiphysis of long bones (near joints—e.g. shoulder, wrist, knee)
What happens to the bone cortex as a result of giant cell tumour, and what does this put the patient at risk for?
Becomes egg-shell thin due to bone resorption
Can rupture, causing hemorrhage
What is the cell lineage of giant cell tumour?
Mesoderm > Reticulum > Blood cell precursors > Giant cell tumour
What is the histological appearance of a giant cell tumour?
Small neoplastic mononuclear cells mixed with giant multinucleated osteoclasts (can have >100 nuclei)
What are 2 treatments for giant cell tumour?
Curettage and bone grafting
What is the prognosis of giant cell tumour?
50% are benign and do not recur
30% recur
20% are malignant
What is the term for a highly malignant tumour seen in children/young adults, unique as it accumulates glycogen?
Ewing sarcoma
What is the underlying cause of Ewing sarcoma?
Genetic mutation: translocation of chromosomal segments
Where does Ewing sarcoma usually occur?
Long bones of limbs
What is the cell lineage of Ewing sarcoma?
Mesoderm > Reticulum > Blood cell precursors > Ewing sarcoma
How does Ewing sarcoma manifest clinically?
Similar symptoms of osteomyelits
How is Ewing sarcoma diagnosed?
PAS stain to detect glycogen
What is the prognosis for Ewing sarcoma?
Good, 5-year survival rate for a localized disease is 75%
What is the term for a malignant tumour of cartilage?
Chondrosarcoma
What demographics does chondrosarcoma usually affect?
Males
Older adults (40-70 yrs)
What is one way that chondrosarcoma is different from osteosarcoma?
Slower growing
Where does chondrosarcoma usually occur?
Spongy bone of spine and pelvis
What are 2 ways chondrosarcoma lead to local destruction of bone?
- Stimulates osteoclasts to resorb bone
- Enlargement of tumour causes erosion of bone cortex and soft tissue impingement
What is the cell lineage of chondrosarcoma?
Mesoderm > Fibroblasts > Chondroblasts > Chondrosarcoma
What are 3 unique characteristics of the appearance of chondrosarcoma?
- Primitive cartilage cells
- Lobules of hyaline cartilage enlarging bone
- Calcification with no new bone
What is the term for a malignant tumour composed of fibroblasts, collagen, and osteoclast-like cells?
Fibrosarcoma
Where does fibrosarcoma usually occur?
Metaphyses of femur or tibia
What is the cell lineage of fibrosarcoma?
Mesoderm > Fibroblasts > Fibrosarcoma
What is the most common type of bone tumour?
Secondary bone tumour
Depending on the primary cancer, what are 3 characteristics that secondary bone tumours may exhibit?
- Osteolytic (increased risk of fracture)
- Bone forming (high density areas of bone)
- Mixed
