IMAGE OF THE WEEK

WEEK 4

 

 

   

FIBROUS DYSPLASIA

 

Fibrous dysplasia is a skeletal developmental anomaly of the bone-forming mesenchyme that manifests as a defect in osteoblastic differentiation and maturation.  The usual appearance of fibrous dysplasia is a lucent lesion in the diaphysis or metaphysis, with endosteal scalloping.  There may or may not be bony expansion. Typically there is no evidence of periosteal reaction, as it is a benign bone lesion. Usually, the matrix of the lesion is smooth and relatively homogeneous; classically described as a ground-glass appearance, where fibrous tissue has replaced the medulla of the bone.  Fibrous dysplasia can be either mono or polyostotic, with monostotic accounting for 70-80% and polyostotic for 20-30%.  It is not a premalignant condition, but there have been occasional reports of osteosarcoma development.  The bone is susceptible to pathological fracture.

 McCune-Albright syndrome is polyostotic fibrous dysplasia associated with precocious puberty and cutaneous pigmented lesions

 

RADIOLOGY

The radiological assessment and classification of bone lesions divides them primarily into aggressive and non-aggressive.

 

 

A number of characteristics are taken into account when assessing a bone lesion, which include:

Single or multiple

Location – epiphysis,metaphysis, diaphysis etc

Zone of transition

Expansile or Non-expansile

Lucent or sclerotic

Periosteal reaction

Matrix composition

 

Images prepared by Dr Ian Bickle, Consultant Radiologist, RIPAS Hospital, Brunei Darussalam.

All images are copyrighted and property of RIPAS Hospital.

 

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