Paget Disease Flashcards
What is another name for Paget disease?
Osteitis deformans
What is the most common metabolic disease worldwide?
osteoporosis
What is the 2nd most common metabolic disease worldwide?
Paget disease
What is Paget disease?
Bone remodeling disorder characterized by accelerated and abnormal remodeling:
- ^resorption of bone
- ^deposition of disorganized bone
What age group is generally effected by Paget disease?
> 50 years
What geographic areas have higher rates of Paget disease?
Northern European populations and areas with high immigration from Britain (eg. Australia, New Zealand, Canada, US)
What geographic areas have lower rates of Paget disease?
- Asia
- Middle East
- Africa
- South America
Paget disease is most likely to be found in which country?
A) Brazil
B) Turkey
C) Japan
D) Scotland
Scotland (northern europe)
What term implies that a bone disorder affects only one bone in the body?
monostotic
What term implies that a bone disorder affects multiple bones, but not all bones in the body?
polyostotic
What is the etiology of Paget disease?
- mutations in genes encoding for proteins in RANK signaling pathway
- infection with paramyxovirus (measles) activates genes
The RANK system induces ____ and ____
osteoclast activity
osteoclastogenensis
What changes to osteoclasts occur in Paget disease?
- multinucleated (>100)
- may contain inclusion bodies
What are inclusion bodies?
Virus-like particles that especially resemble paramyxoviruses (measles)
Most cases of Paget disease are (monostotic/polyostotic)
monostotic
Where is Paget disease commonly found in the body?
axial skeleton
- spine
- skull
- pelvis
- femur
- tibia
- humerus
Name the radiographic characteristics of Paget disease
- bony expansion
- cortical thickening
- extensive trabecular patterns
How is Paget disease differentiated from metabolic diseases?
Paget disease is usually monostotic, unlike metabolic diseases which have generalized skeletal involvement
What diagnostic method would determine whether a case of Paget disease is monostotic or polyostotic?
bone scan (can look at all bones at once)
Name the stages of Paget disease?
- Lytic
- Mixed
- Blastic
- Malignant transformation (debated)
If Pagetic bone undergoes malignant transformation, it will become a(n) ____
osteosarcoma
Which stage of Paget disease is described as “hot” and why?
stage 1 - osteoclastic resorptive stage (lytic stage)
^vascularization of Pagetic bone
What occurs during stage 1 of Paget disease?
- widespread osteolysis
- marrow fibrosis (fibrous replacement of marrow)
- dilation of marrow sinusoids
Marrow fibrosis in polyostotic Paget disease would increase the risk of ____
anemia (decreased blood cells)
How would stage 1 of Paget disease appear radiographically?
“blade of grass” or “candle flame”
(tapered appearance where there is less bone)
Bone scans show ____ activity, which occurs in reaction to ____ activity in Paget disease
blastic
lytic
How does stage 2 of Paget disease appear radiographically?
- bones appear larger (bony expansion)
- thickened cortex, accentuation of cancellous bone
- “picture frame” appearance of vertebral bodies
- protrusio acetabuli
What is protrusio acetabuli?
Acetabulum protrudes into pelvis, seen radiographically where the femoral head crosses the ilio-ischial line (Kohlers’s line)
In what stage of Paget disease is osteoclastic activity slowing down, while osteoblastic activity is catching up?
Stage 2: mixed osteoclastic & osteoblastic stage