Bone & Cartilage Tumors - Hunt Flashcards
What is your first suspicion when seeing a cancerous lesion in bone?
Metastatic lesion. Primary bone tumors are quite rare; 0.2%.
How do bone lesions present clinically?
Often asymptomatic, but sometimes with pain, palpable mass, or pathologic fracture.
Describe some characteristic bone lesions of the following age groups:
Children
Young adults
The elderly
Children: Osteosarcoma & Ewing’s sarcoma :(
Young adults: Giant cell tumor
Elderly: Chondrosarcoma
Recall the three different sites of lesions in long bones. See if you can name lesion characteristic to each region.
Epiphysis (eg Giant cell tumor)
Metaphysis (eg Osteosarcoma, many others)
Diaphysis (eg Ewing’s sarcoma)
Describe how bone tumors present on X-ray imaging.
Benign or slow-growing tumors feature a sclerotic region (distinct rim), while malignant growths are more ill-defined.
Characteristic matrix formation may be present (eg solid, ivory-like pattern of bone deposition, or rings/arcs of cartilage).
Distinguish between osteoid osteomas and osteoblastomas.
Both are benign. Very similar histologies.
Osteomas are smaller, cause night pains, are responsive to aspirin, and have a clear lesion edge.
Osteoblastomas are larger, do not respond to aspirin, have a more mottled appearance and may affect vertebrae.
Osteosarcoma
How common is it?
Who is at greatest risk?
Osteosarcoma
The most common bone sarcoma, but still exceedingly rare (~2k/yr)
Incidence: M>F, mean age 15.
Osteosarcoma
Describe some possible causes of osteosarcoma.
Why is their prognosis so poor?
Osteosarcoma
Inherited mutations of Rb/p53, or overexpression of MDM2/INK4/p16.
They tend to be clinically silent until after metastasis to lungs.
Osteosarcoma
How does it appear on X-ray?
What is a codman’s triangle?
Osteosarcoma
It is poorly delineated with marked bone/cortical destruction. May have local bone or cartilage remodeling.
A codman’s triangle is an extension of periosteum being pulled away by the rapidly growing tumor.
Osteosarcoma
How is it treated?
Osteosarcoma
Surgical resection (ideally limb-sparing), and chemotherapy.
What is the most common tumor of cartilage (and bone, for that matter)?
Describe its pathogenesis and characteristics.
Osteochondroma.
Autosomal dominant inheritance of EXT-1 mutation (8q24) results in metaphyseal tumors with bony spurs.
Distinguish between enchondromas and periosteal chondromas.
Both are benign cartilage tumors. Enchondromas are within bones (intramedullary), while periosteal chondromas are juxtacortical.
Enchondroma
Where do they typically appear?
How are they usually diagnosed and treated?
Enchondroma
In the appendicular skeleton (eg phalanges).
Accidentally! Usually asymptomatic, but feature cortical thinning and replacmeent with cartilage. Treatment only indicated if lesion shows changes or symptoms.
Distinguish between Ollier’s disease and Maffucci’s syndrome.
These are both conditions that result in multiple chondromas, probably resulting from IDH1/2 mutations. Both may cause skeletal malformation.
Ollier’s disease are regionally distributed.
Maffucci’s syndrome also features angiomata, and is generally higher risk for malignant transformation.
Chondrosarcoma
Who is at highest risk for a chondrosarcoma?
How common are they?
Chondrosarcoma
Old fogies; peaks during 6th-7th decades.
Second most common bone tumor (presumably most common cartilaginous tumor)
