Benign & Malignant Bone Tumours Flashcards
State at least 3 differences between benign and malignant bone tumours
Benign = no periosteal reaction, malignant = acute periosteal reaction Benign = thick endosteal reaction, malignant = broad border between lesion and normal bone Benign = well-developed bone formation, malignant = varied bone formation Benign = intraosseus and even calcification, malignant = extraosseus and irregular calcification
Describe the acute periosteal reaction seen in malignant bone tumours
Cortex showing Codman’s triangle (triangular area of new subperiosteal bone created when the periosteum is raised away from the bone), onion skin, sunburst
State the typical age of onset of osteosarcoma
Adolescence
State the typical age of onset of Ewing’s sarcoma
<20 years
State the typical age of onset of giant cell tumours
20-40 years
State the typical age of onset of chondrosarcoma
> 40 years
State the most common site of osteosarcoma
Knee
State the most common site of giant cell tumours
Epiphysis of knee
State the most common sites of Ewing’s sarcoma
Long bones, pelvis
State the most common sites of chondrosarcomas
Axial skeleton, femur, tibia, pelvis
Describe the histological appearance of osteosarcoma
Malignant mesenchymal cells, positive for ALP
Describe the histological appearance of chondrosarcoma
Malignant chondrocytes
Describe the histological appearance of Ewing’s sarcoma
Sheets of small round cells positive for CD99. Genetic analysis shows t(11;22)
Describe the histological appearance of giant cell tumours
Osteoclast-type multinucleate giant cells on background of spindle or ovoid cells
Describe the x-ray appearance of osteosarcoma
Elevated periosteum (Codman’s triangle), sunburst appearance
Describe the x-ray appearance of chondrosarcoma
Lytic lesion with fluffy calcification
Describe the x-ray appearance of Ewing’s sarcoma
Onion skinning of periosteum
Describe the x-ray appearance of giant cell tumours
Lytic or lucent lesions right up to the articular surface
State the most common sites of osteoid osteoma
Tibial diaphysis, proximal femur
State the most common sites of osteoma
Head and neck
State the most common sites of enchondroma
Hands
State the most common sites of osteochondroma
Metaphysis of long bones near tendon attachment sites
State the most common site of fibrous dysplasia
Femur
Name 4 malignant bone tumours
Osteosarcoma, chondrosarcoma, Ewin’s sarcoma, giant cell tumour (borderline malignant)
Name at least 4 benign bone tumours
Osteoid osteoma, osteoma, endochondroma, osteochondroma, fibrous dysplasia, simple bone cyst, osteoblastoma
Describe osteoid osteoma
Small benign bone forming lesion causing pain at night, relieved by aspirin. Histology shows normal bone
Define osteoma
Bony outgrowths attached to normal bone. Histology shows normal bone
Define Gardner syndrome
Multiple osteomas, gastrointestinal polyps, and epidermoid cysts
Define enchondroma
Benign tumours of cartilage. Histology shows normal cartilage
Define Maffuci’s syndrome
Multiple enchondromas and haemangiomas
Define osteochondroma
Cartilage capped bony outgrowrh
Define diaphyseal aclasis
Hereditary multiple exostoses with short stature and bone deformities
Define fibrous dysplasia
Replacement of bone by fibrous tissue. ‘Chinese letters’ (misshapen bone trabeculae) on histology
Describe the features of Albright syndrome
Polyostotic fibrous dysplasia with café au lait spots and precocious puberty
Describe the x-ray appearance of osteoid osteoma
Radiolucent nidus with sclerotic rim - Bullseye appearance
Describe the x-ray appearance of enchondroma
Lytic lesion with cotton wool calcification. O ring sign
Describe the x-ray appearance of osteochondroma
Well defined bony protuberance, cartilage capped - mushroom appearance
Describe the x-ray appearance of fibrous dysplasia
Soap bubble osteolysis, Shepherd’s crook deformity
Describe the x-ray appearance of osteoblastoma
Speckled mineralisation
