olystotic F more aggressive than m
The lesions usually progress in number till the end
of skeletal maturation, by then they become
in only about 5% of cases it continue to enlarge
Complications of fibrous dysplasia
Massive cartilage hyperplasia.
Accelerated bone growth.
is very rear, it may occur
following radiation therapy.
Extraosseous soft tissue
Long bones specially the neck of femur
Skull (including calvarium, skull base, facial bones
Ribs (fibrous dysplasia is the most common cause
of rib expansion).
Unilateral or rarely bilateral asymmetrical.
Long bone fibrous dysplasia
Meta-diaphyseal. The epiphysis is usually spared.
May be expansile.
Cortex thinned or scalloped with no cortical break through or
periosteal reaction (smooth outer cortex).
depend upon the ratio between the fibrous & osseous tissues,
Sclerotic (increased osseous content), or
Lytic (increased fibrous content) or
Ground glass, (relatively equal ratios between fibrous & osseous content).
Well defined sclerotic margin (Geographic bone destruction).
The sclerotic margin may be thick (rind sign).
Pelvis fibrous dysplasia
Expansile, lytic, bubbly lesion.
The degree of expansion & the bubbly nature
are quite marked in the pelvis rather than long
Rib fibrous dysplasia
Expansile lytic lesion with no rib destruction.
Widening of the diploic space.
Displacement of the outer table.
Sparing of the inner table.
Narrowing of the neural
•Lytic or mixed
•Sclerotic or Ground glass,
Skull base tumors
(the inner table is involved).
Fibrous dysplasia conforms to
the shape of the involved bone.
Special forms of fibrous dysplasia
Mc Cune Albright syndrome.
A special form of polystotic fibrous dysplasia that
affects the skull & facial bones.
Familial fibrous dysplasia of the jaws.
Mc Cune Albright
Almost exclusively affect females.
Mc Cune Albright syndrome
Never cross the midline and
(coast of Maine)
Cross the midline.
(coast of California)