malignant transformation

Multiple Hereditary Exostosis

AKA

 

Diaphyseal Aclasis / Multiple Osteochondromas

 

Definition

 

Heritable skeletal dysplasia

 

Epidemiology

 

AD with variable penetrance (96%)

 

Malignant Transformation

 

Incidence of malignant transformation much higher 

- 10% overall

- 1 % / year

 

Chondrosarcoma (CS) > Osteosarcoma (OS)

 

Giant Cell Tumour of Bone

Definition

 

Benign lesion with a wide spectrum of behavior characterized by stromal cells and giant cells

 

Epidemiology

 

Common

- 20% of benign tumours

 

More common females

- F:M = 1.5:1

- most tumours M>F

 

Usually patient in 20's

- usually after skeletal maturity

- 3% < epiphyseal closure

 

Fibrous Dysplasia

Definition

 

Developmental hamartoma in which areas of the skeleton fail to mature normally

- remain indefinitely as immature, poorly mineralized trabeculae

 

Pathology

 

Hamartoma of bone and fibrous tissue

 

McCune - Albright's Syndrome

 

Rare triad of

 

1.  Fibrous Dysplasia