Paget Disease Flashcards
Paget disease is also called ___
osteitis deformans
What is Paget disease?
Bone remodeling disorder characterized by accelerated and abnormal remodeling
Paget disease features ___ resorption of bone and ___ bone deposition
excessive resorption of bone
excessive, disorganized bone deposition
What demographic is most commonly affected by Paget disease?
- Generally, individuals >50 years of age
- Common in Northern European populations (and places they’ve immigrated to)
Paget disease affects ___% of the world population over 50
3%
Paget disease has a very low incidence in ___
Asia, Middle East, Africa, and South America
Is Paget disease monostotic or polyostotic?
Can be either
What does it mean if Paget disease is monostotic?
Affects one bone, active while child is growing, often inactive after puberty
What does it mean if Paget disease is polyostotic?
Affects multiple bones and affects individual throughout life
Paget disease involves mutations in genes encoding for ___
proteins in the RANK signaling pathway
Paget disease involves mutations in genes encoding for proteins in the RANK signaling pathway
What does the RANK system induce?
Induces osteoclast activity and osteoclastogenesis
What are some osteoclast changes that occur with Paget disease?
- Above normal numbers of nuclei (Pagets >100 nuclei vs normal <12 nuclei)
- May contain virus-like particles
Which bones of the axial skeleton may be affected by Paget disease?
- Spine
- Skull
Which bones of the appendicular skeleton may be affected by Paget disease?
- Pelvis
- Femur
- Tibia
- Humerus
What are the 3-4 stages of Paget disease?
- Lytic
- Mixed
- Blastic
- Malignant transformation
About ___% of patients with Paget reach the malignant transformation stage
1%
Stage 1 of Paget, the lytic stage, is also called ___
osteoclastic resorptive stage/hot stage
In which stage of Paget disease will the following present?
- Widespread osteolysis
- Marrow fibrosis
- Dilation of marrow sinusoids
- “Blade of grass”/”candle flame” radiography
Stage 1 - osteoclastic resorptive stage
In which stage of Paget disease will the following present?
- Bones appear larger radiographically
- Thickened cortex, accentuation of cancellous bone
Stage 2 - mixed osteoclastic and osteoblastic stage
In which stage of Paget disease will the following present?
- Histologically, minimal activity
- Radiographically, thickened and disordered bone
Stage 3 - burnt out/blastic stage
What are some presentations of stage 1 Paget disease?
- Widespread osteolysis
- Marrow fibrosis
- Dilation of marrow sinusoids
- “Blade of grass” or “candle flame” radiographically
What are some presentations of stage 2 Paget disease?
- Larger bones in radiographs
- Thickened cortex, accentuation of cancellous bone
Stage 3 of Paget disease, the blastic stage is also known as ___
Burnt-out/cold stage
What are the histological differences found in stage 3 Paget disease bones?
Mosaic pattern in bone with irregular cement lines
What stage of Paget disease is present if bone histologically displays a mosaic pattern with irregular cement lines?
Stage 3 - burnt-out/cold stage
Neoplastic transformation of Paget disease is typically seen in which cases?
Severe polyostotic cases
Which types of neoplasm may occur in Paget disease?
- Osteosarcoma
- Chondrosarcoma
- Fibrosarcoma
What stage of Paget disease will present osteoporosis circumscripta in the skull?
Stage 1 (lytic phase)
What is osteoporosis circumscripta?
Localized lysis in the skull, usually frontal and parietal bones
Occurs during phase 1 of Paget disease
If the following has occurred to the skull, what phase of Paget disease is present?
- Thickening of inner and outer tables
- Platybasia
- Skull is heavy and collapses on C1
Mixed/blastic phases: cotton wool skull
If the following has occurred to the skull, what phase of Paget disease is present?
- Misshapen jaw
- Tooth loss
- Facial bones may increase in size
Mixed/blastic phase: cotton wool skull
Mixed/blastic phase of Paget disease presenting cotton wool skull may display platybasia.
What is platybasia?
Flattening of the base of the skull; can compress medulla or spinal cord
Mixed/blastic phase of Paget disease presenting cotton wool skull may make the skull too heavy and collapse on C1.
What is a direct consequence of this?
Brain or spinal cord compression
Mixed/blastic phase of Paget disease may present with leontiasis ossei
What is leontiasis ossei?
Lion face; facial bones increase in size
What is the IHOP mnemonic for ivory vertebrae?
Idiopathic
Hodgkins lymphoma
Osteoblastic metastasis
Paget’s disease
What are possible presentations of the spine with Paget disease?
- Ivory vertebra
- Picture frame vertebra
- Possible spinal stenosis (narrowing)
Paget disease can cause vertebral canal stenosis/narrowing
What is the direct result of this?
Spinal cord compression
What is the deformity of tibia seen in Paget disease?
Sabre shin: coarse trabecular expansion at anterior tibia
What kinds of fractures occur to a tibia with Paget disease?
- Pseudofractures (convex side)
- Transverse fractures (banana fracture)
Pagetic bone is highly vascular.
What are some results of this?
- Pagetic steal (paraparesis or paraplegia)
- Cardiomegaly
- High output cardiac failure
What are some clinical manifestations of Paget disease?
- Frequently asymptomatic
- Pain in the affected area
- Increased osteoarthritis
- Pathologic fracture
- Headaches
- Hearing loss
- Hat size changes
A patient complains of headaches, hearing loss, and mentions that their hat size has changed
What disease is suspected?
Paget disease
With Paget disease, serum calcium and phosphate levels are:
normal
With Paget disease, serum alkaline phosphatase levels are ___
elevated
With Paget disease, ___ is elevated in urine
hydroxyproline
With Paget disease, ___ is elevated in serum
hydroxylysine
What symptoms are managed when a patient has Paget disease?
Fractures and osteoarthritis
What are some pharmaceutical treatments for Paget disease?
Osteoclast inhibitors:
- Calcitonin
- Biphosphonates like Fosamax
Pagetic steal is caused by the over proliferation of vasculature in dense disorganized bone tissue causing patients to experience ___
spinal cord compression
Stage 1 of Paget disease is characterized by increased ___
osteoclastic activity
True or False:
Paget disease patients have an increased risk of developing a malignant bone tumor
True, but rarely
