Paget Disease Flashcards
What populations have higher incidence of Paget disease?
- United Kingdom
- Australia (British ancestry)
- New Zealand (British ancestry)
- Canada (British ancestry)
What populations have lower incidence of Paget disease?
- Asia
- Africa
- Scandinavia
What age group is generally effected by Paget disease?
> 55 years
Paget disease is most likely to be found in which country?
A) Brazil
B) Turkey
C) Japan
D) Scotland
Scotland (northern europe)
What is the etiology of Paget disease?
- unknown, multiple theories
- possibly paramyxovirus (measles) activates genes
Where is Paget disease commonly found in the body?
(any bone) R > L side
- spine
- skull
- pelvis
- femur
- tibia
- humerus
Name the primary radiographic characteristics of Paget disease
- bony expansion
- cortical thickening
- extensive trabecular patterns
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 (Dx = Paget sarcoma)
Which stage of Paget disease is described as “hot” and why?
stage 1 - osteoclastic resorptive stage (lytic stage)
^vascularization of Pagetic bone
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 of tubular bones)
- osteoporosis circumscripta (skull)
Bone scans show ____ activity, which occurs in reaction to ____ activity in Paget disease
blastic
lytic
How can Paget disease be differentiated from metastasis?
metastasis doesn’t change size of bone, while Paget disease shows bony expansion
In what stage(s) is Paget disease most commonly found?
Stages 2 & 3
How does stage 3 of Paget disease appear radiographically?
thickened & disordered bone
- ivory vertebra
- brim sign
What stage of Paget disease is typically seen in severe polyostotic cases?
Stage 4: malignant transformation
The lytic phase of Paget disease in the skull is called ____
osteoporosis circumscripta
What is osteoporosis circumscripta? Where does it usually occur?
localized/solitary lysis in the skull (stage 1), usually frontal & parietal bones (calvarium)
The mixed/blastic phases of Paget disease in the skull creates the appearance called ____
cotton wool skull
What is Leontiasis Ossei?
“lion-like face”
increase in facial bone size due to Paget disease in the skull
What are the radiographic findings of Paget disease in the spine?
- ivory vertebra
- “picture frame” vertebrae on lateral view
In Paget disease in the spine, bone gets bigger in what dimension?
laterally (A-P + M-L)
(bone softening, will compress bones, not allowing vertically)
What is a possible consequence of Paget disease in the spine? How would this manifest clinically?
- vertebral canal stenosis/narrowing (bone expands inward)
- provoked in extension, feels better in flexion
- seen radiographically as ivory vertebra w/ bony expansion
How does Paget disease appear in the tibia?
- sabre shin (may affect gait)
- pseudofractures
- transverse fractures
What term describes the course trabecular expansion creating the appearance of a curved anterior tibia?
sabre shin
What term describes a “seam” of unmineralized osteoid?
pseudofracture
Where do pseudofractures occur in Pagetic long bones?
convex side
In what conditions might you see pseudofractures?
PROF:
- Paget disease
- Rickets
- Osteomalacia
- Fibrous dysplasia
In a patient with pseudofractures, how is Rickets differentiated from Paget disease?
Rickets occurs in young population
In a patient with pseudofractures, how is Osteomalacia differentiated from Paget disease?
osteopenic change in osteomalacia
In a patient with pseudofractures, how is Fibrous dysplasia differentiated from Paget disease?
occurs on concave side in Fibrous dysplasia
Transverse fractures are also called ____
banana fracture
What are the radiographic signs of Paget disease in the pelvis and hips?
- brim sign
- teardrop sign
- Otto pelvis (= BL protrusio acetabuli)
- shepherd’s crook deformity
What is the clinical presentation of Paget disease?
- age >55 yrs
- 90% asymptomatic
- mild bone pain in affected area
- patho Fx
- bowing/deformity
- hyperkyphosis
- headaches/hat size changes (lol)
What are the findings of diagnostic labs for Paget disease?
- normal Ca2+ and PO
- ^alkaline phosphatase
- ^urinary hydroxyproline
What is the treatment for Paget disease?
- none, if asymptomatic
- manage symptoms (brace deformities; Fx & osteoarthritis)
- refer to rheumatology: osteoclast inhibitors (calcitonin & bisphosphonates)
What is protrusio acetabuli?
Acetabulum protrudes into pelvis unilaterally, seen radiographically where the femoral head crosses the ilio-ischial line (Kohlers’s line)
In what stage of Paget disease is “picture frame” vertebrae found?
mixed/blastic stages
(on lateral view)
Hydroxyproline and hydroxylysine are large components of ____
collagen
What levels of hydroxyproline and hydroxylysine would be found in diagnostic labs for Paget disease and why?
- increased hydroxyproline > hydroxylysine
- both are components of collagen
- ^turnover of osteoid + destruction in Paget disease
What is an example of a bisphosphonate given for treatment of Paget disease?
Fosamax
What is teardrop sign?
Kholer’s teardrop is filled in with Pagetic bone radiographically
What is brim sign?
thickened cortex of pelvic brim seen radiographically in Paget disease
If you see an ivory vertebra with bony expansion what complication are you concerned about?
(Dx: Paget disease)
spinal stenosis
Name 7 common complications of Paget disease.
- Shepherd’s crook deformity
- saber shin
- otto pelvis
- leontiasis ossei
- basilar invagination
- genu varum
- patho Fx
Name 7 uncommon complications of Paget disease
- anemia
- high output cardiac failure
- ureteric colic
- pseudoFx
- spinal stenosis
- degenerative Dz
- malignant transformation
What are the ominous signs of malignant degeneration of Paget disease?
- increasing pain
- enlarging mass
- enlarging osteolytic lesion
- increasing alk phos.
How common is malignant degeneration of Paget disease (Paget sarcoma)?
1-2% of pts w/ Paget Dz
What is the most important radiographic feature?
Extensive trabecular pattern
(Dx: Paget Dz)
Name 2 radiographic signs seen here.
- brim sign
- tear drop sign
(Dx: Paget Dz)
What radiographic sign is demonstrated?
Saber shin (with pseudofractures)
Give 2 differentials in order from most to least likely. What feature helps to narrow this diagnosis?
Pseudofractures
1. Paget Dz (convex side)
2. Fibrous Dysplasia (concave side)
What radiographic sign is demonstrated? What does this tell you about the diagnosis?
Candle flame / blade of grass appearance = lytic phase of Paget Dz
What is the differential mnemonic for this case? Which is the most likely?
Ivory vertebrae = IHOP
- Idiopathic (exclusion)
- Hodgkins Lymphoma (ant body scalloping)
- Osteoblastic Mets (no expansion or ant scalloping)
- Paget Dz (bony expansion)
What sign is demonstrated? What does this tell you about the diagnosis?
Osteoporosis circumscripta = lytic phase of Paget Dz in skull
What sign is demonstrated? What does this tell you about the diagnosis?
Cotton wool skull = mixed/blastic phase of Paget Dz in skull
What is the diagnosis?
Paget sarcoma
