10. Fibrous Dysplasia and Pagets Flashcards
Three types of Fibrous Dysplasia
- Monostotic fibrous dysplasia 70% ~age 14
- Polyostotic fibrous dysplasia 27% ~ age 11
- Polyostotic fibrous dysplasia with endocrine abnormalities
(McCune-Albright Syndrome) ~3% ~ age 8
Slowly progressing benign disorder of fibro-osseous tissue throughout life replacing normal bone tissue
Fibrous Dysplasia
“Great Imitators of Bone Disease”
Fibrous Dysplasia and Paget’s disease
Polyostotic FD may have
bowing deformities and pathologic fx
Shepherd’s Crook deformity and Leg length discrepancy
Polyostotic FD
Enlargement and deformity of cranial
and facial bones
Leontiasis Ossea
Dark brown pigmented skin macules due to increased melanin in epidermis
Café au Lait Spots (Coast of Maine appearance)
ground-glass matrix
Fibrous Dysplasia
ground-glass matrix is
due to lack of
normal
cortical and
trabecular organization
most common etiology of benign rib lesions
Fibrous dysplasia
Main Pathologic Process of Café au lait spots is proliferation of
Melanocytes
Higher incidence of pathologic fx and Shepherd’s Crook deformity
Polyostotic FD
polyostotic FD with skin
pigmentation and precocious sexual development in Females
McCune-Albright Syndrome
occasional increase in alkaline
phosphatase and osteocalcin
Fibrous dysplasia
Multilocular cystic lesions with asymmetric distribution in mandible and maxilla and lower face swelling
cherubism
“Eyes raised to heaven attitude”
cherubism
Familial multilocular cystic disease of the jaws
cherubism
Bone is replaced by abnormal proliferation of fibrous tissue and poorly formed bony trabeculae of woven bone
Fibrous Dysplasia
Monostotic FD is mc in
ribs and proximal femur
Radiolucent Loculated, trabeculated, Ground glass or smokey appearance and Spares subarticular surface of bone
Monostotic FD
Thick sclerotic margin in Monostotic FD, aka a
rind of sclerosis
Symptoms of Polyostotic FD are usually from
bowing deformities and pathologic fx
Incomplete septa or ridges in Polyostotic FD result in
loculation of lesions
along convex surface of deformed cortex
Pseudofractures
may occur in areas of pathologic fx nonunion
Pseudoarthrosis
may look like FD in skull
Stage 2 of Paget’s
Paget’s thickens outer table of skull, whereas FD ____ outer table
thins
not commonly involved by FD
Spine
Paget’s Disease, Aka
osteitis deformans
Osteolysis followed by extensive attempts at repair
Paget’s Disease
Common in England, Australia, and New Zealand
Paget’s Disease
may have contributed to Beethoven’s
loss of hearing
Paget’s disease
Pain from microscopic fx, increased blood flow, joint destruction, mechanical destruction of bone, and Increase in hat size and shoe size
Paget’s
Hallmark of Pagets
Bony enlargement
Shepherd’s Crook deformity, Sabre Shin deformity, and Basilar invagination
Pagets
May cause brainstem compression, syringomyelia, or
obstructive hydrocephalus
Basilar invagination
- Pseudofractures
- Sabre Shin Deformity
- Bony Enlargement
- Out of focus appearance
Paget’s Disease
“cotton ball” or “cotton wool” appearance
Paget’s Disease
enlarged, sclerotic hemipelvis with joint space loss
Pagets
mc complication of Pagets
pathologic fracture
Local areas of demineralized bone in Pagets may result in
banana fracture (bilateral/symmetrical)
Spinal Stenosis from bone expansion in Paget’s Disease leads to
compressive neuropathy and Possible cauda equina
Weakness in legs, urinary incontinence, sensory disturbances
cauda equina
Due to hypercalcemia and hypercalciuria in Paget’s Disease
Urinary Calculus formation
Pagetic bone has 20X
normal vascularity
Extensive Paget’s may result in
cardiac congestive failure (Need at least 1/3rd of skeleton involved)
what % of patients with Paget’s disease are
asymptomatic?
90%
Paget’s Sarcoma prognosis
rapidly fatal
Paget’s begins in _______ region of long bone
subarticular
least likely bone to be affected by Paget’s
Fibula
Elevated Alkaline phosphatase and hydroxyproline
Paget’s
- Bone destruction replaced by fibrous tissue and osteoid
that may calcify
– Possible hemorrhage and necrosis
– Marked vascularity of bone
Paget’s Disease
“Mosaic Structure of Paget’s disease” results from
simultaneous Destruction and repair
Paget’s shows
increased uptake on bone scan due to
hypervascularity
Osteoclastic overactivity creates loss of bone
density and Osteoporosis Circumscripta
Paget’s Disease Stage 1
miexed and mc stage seen with cheap fibrous bone replacement following bone destruction
Paget’s Disease Stage 2
helps to distinguish Paget’s disease from sclerotic metastases
osseous enlargement
Cotton Wool Appearance
Paget’s Disease Stage 2
picture frame vertebra and cotton-wool appearance (skull)
pagets stage 2
Abnormal lucency in the distal femur with a flame-shaped or
“blade of grass” shaped
proximal margin caused by the
`advancing lytic phase of Paget’s disease
Sclerotic or Ivory stage of paget’s
Stage 3
Malignant Transformation seen in what stage of Paget’s?
Stage 4 (Osteosarcoma mc)
Prostate metastasis elevates
acid phosphatase
Pagets affect on pelvis
- Cortical thickening
- Expansion of pubis and ischium
- Patchy sclerosis
- Intermittent lucent defects
- Increased trabeculae
- rim or brim sign
- Protrusio acetabuli
Begins as subarticular lesion, Shepherd’s Crook deformity, and Pseudofractures
Paget’s in the femure
blade of grass appearance aand sabre shin deformity
Paget’s in the tibia
Paget’s treatment
- Human and salmon calcitonin to inhibit bone resorption
- Bisphosphonates
- Supportive bracing to prevent deformities
