OSTEOCHONDROMA

• Cartilage capped exostosis

• Commonest benign tumour of bone

• Metaphyseal developmental abnormality

D FRANTZEN OSTEOCHONDROMA

INCIDENCE• 45 % of benign bony tumours

• 12 % of all bony tumours

• Become evident < 20 yrs

• Solitary or multiple

• Any enchondral ossification bone

D FRANTZEN OSTEOCHONDROMA

CLINICALLY

• Lump or mechanical problem

• Tendon or nerve irritation

• Sessile or pedunculated

• 50% distal femur, proximal tibia, proximal humerus

D FRANTZEN OSTEOCHONDROMA

CLINICAL

• Active growth during puberty

• Move towards diaphysis during growth

• Excise if troublesome in second decade

D FRANTZEN OSTEOCHONDROMA

RADIOLOGY

• Flat/ sessile / pedunculated

• Tumour blending into metaphysis

• Pedunculated orientated proximally

• Cartilage cap with calcification

D FRANTZEN OSTEOCHONDROMA

PATHOLOGY

• Normal bone covered by normal cartilage cap

• Cartilage cap resembles normal growth plate

• Cartilage more disorganized

D FRANTZEN OSTEOCHONDROMA

PATHOLOGY

• Covered by thin layer of periosteum

• Binucleate chondrocytes in lacunae

D FRANTZEN OSTEOCHONDROMA

TREATMENT

• Nil required unless symptomatic

• Extra-capsular marginal excision

• Recurrence < 5%

D FRANTZEN OSTEOCHONDROMA

PROGNOSIS

• Risk of malignancy if solitary - 0.2 %

• Risk of malignancy in diaphyseal aclasia : - 20 %

• Sarcomatous changes usually low- grade

D FRANTZEN OSTEOCHONDROMA