Neoplastic bone disease

Question 1

Osteosarcoma: age, bone affected, histology (1), x-ray appearance (2)

Answer 1

• 0-20yr olds
• Knee most common
• Histo
  
  • malignant mesenchymal cells
  • ALP raised
• X-ray appearance
  
  • elevated periosteum - dense layer of vascular tissue enveloping bones (codman’s triangle)
  • sunburst appearance (due to periostitis)

Question 2

Chondrosarcoma: age, histology, x-ray appearance (1)

Answer 2

Cancer derived from cells that produce cartilage, happens in >40yr olds.

Hist - malignant chondrocytes

x-ray - lytic lesion with fluffly calcification, axial skeleton

Question 3

Ewing’s sarcoma: age, bones, histo (3), x-ray (1)

Answer 3

Childhood cancer, mainl in long bones/ pelvis

Histo:

• sheets of small round cells
• CD99+
• T11:22 translocation

X-ray

• onion skinning of periosteum

Question 4

Giant cell tumour (borderline malignancy): F>M, bone, histo (2), x-ray appearance (1)

Answer 4

Knee epiphysis

• osteoclast-type multinucleate giant cells
• on background of spindle/ovoid cells (Soap bubble)
• X-ray - lytic lesions right up to articular surface

Question 5

Benign bone tumours: Osteoid osteoma (adolescent) - bone, features (2), histo, x-ray (1)

Answer 5

• bone - tibia/femur

F - small benign bone forming lesion. Night pain relieved by aspirin

Hist - normal bone

X-ray - Radiolucent nidus with sclerotic rim

Question 6

Benign bone tumours: Osteoma (middle age)

• bone
• features (2)
• histo

Answer 6

• head & neck affected
• bony outgrowths attached to normal bone
• gardner’s syndrome - GI polyps + multiple osteomas + epidermoid cysts
• Histo - normal bone

Question 7

Benign bone tumours: Endochondroma (middle age)

• bone
• features (2 syndromes)
• histo
• xray - 3

Answer 7

Hands

• benign tumours of cartilage
• ollier’s syndrome = mutliple enchondromas
• maffuci’s syndrome = multiple enchondromas + haemagniomas

Histo - normal cartilage

X-ray

• Lytic lesion
• cotton wool calcification
• expansile, O ring sign

Question 8

Benign bone tumours: Osteochondroma (= exostosis) <25yr

• features (3)
• histo (1)
• x-ray (1)

Answer 8

• cartilage capped bony outgrowth
• diaphyseal aclasis/ hereditary multiple exostoses = short stature + multiple exostoses + bone deformities

Histo - cartilage capped bony outgrowth

X-ray - well define bony protuberance from bone

Question 9

Benign bone tumours: Fibrous dysplasia - middle age F>M

Bone (1), features (2), histo (1), x-ray (2)

Answer 9

• Femur

F

• a bit of bone is replaced by fibrous tissue
• albright syndrome = polyostotic dysplasia + cafe au lait spots + precocious puberty

Histo - Chinese letters (misshapen bone trabeculae)

X-ray - Soap bubble osteolysis & shepherd’s crook deformity

Question 11

Benign bone tumours: Simple bone cyst

feature, x-ray

Answer 11

Affects humerus or femur

Fluid filled unilocular

x-ray - lytic well defined

Question 12

Benign bone tumours: Osteoblastoma

x-ray change (1)

Answer 12

Similar to osteoid osteoma

speckled mineralisation