tumour like lesions Flashcards
Fibrous dysplasia Osteofibrous dysplasia Paget's disease Eosinophilic granuloma Myositis ossificans Melorheostosis Heterophic ossifications tumoral calcinosis Bone Infarct focal fibrocartilaginous dysplasia
1
Q
What is fibrous dysplasia?
A
- A developmental abnormality caused by failure of the production of normal lamellar bone
- areas of the skeleton remain poorly mineralised tabeculae
- females > males
- found any ages
- **75% pts <30 yrs **
- location
- any bone can be involved
- Prx femur, rib, maxilla and tibia
2
Q
What are the genetics of fibrous dysplasia?
A
- GS alpha protein ( chromosome 20q13) activating mutation
- Affects cAMP signalling pathway -> increased production of cAMP
- not inherited
- high production of FGF-23 may-> hypophosphataemia
3
Q
Name the associated conditions of fibrous dysplasia?
A
-
McCune Albright Syndrome
- cafe au lait spots in coast of maine- sharp/irreg
- Preococious puberty
- renal phosphate wasting due to FGF-23( oncogenic osteomalacia)
- unilateral polyostotic fibrous dysplasia
-
Mazabraud syndrome
- polyostotic fibrous dysplasia
- soft tissue intramuscular myxomas
-
Osteofibrous dysplasia
- rare form that primarily affects the tibia & is confined to cortices
4
Q
What is the prognosis of fibrous dysplasia?
A
- 1% risk of malignant transformation to
- osteosarcoma
- fibrosarcoma
- malignant fibrous histocytoma
- Poor prognosis
5
Q
What is the presentation/symptoms of fibrous dysplasia?
A
- Swelling or deformity
- lesions maybe
- monostotic 80%
- polyostotic 20%
- Pain from stress fx
On examination
-
cafe au lait spots- maybe present
- larger/irreg border cf NF spots
6
Q
What are the radiographs of fibrous dysplasia?
A
-
Central lytic lesion in medullary canal( diaphyseal/metaphyeal)
- may have cortical thinning w expansile lesion
- Highly lytic lesion/ ground glass appearance
- “punched out lesion” sclerotic margin
- Shepherd’s crock deformity
- vertebral collapse & kyphoscoliosis
- Bone scan- usually warm
7
Q
What does histology of fibrous dysplasia show?
A
- typical “Alphabet soup/ chinese letters”
-
fibroblast proliferation surrounded by woven bone
- woven bone lacks osteoblastic rimming
8
Q
What is the tx of fibrous dysplasia?
A
Non operative
-
Observation
- asymptomatic pts
-
Bisphosphonate therapy
- for symptomatic polyostotic fibrous dysplasia
- effective in reducing pain/ bone turnover
Operative
-
Internal fixation and Bone grafting
- symptomatic lesions/ impending/actual fx/ severe deformity
- never use autogenous BG as bone will turn into FB use cortical/canc allograft
- IM nails more effective than plating in Lower limb
-
Osteotomies
- for deformity
9
Q
What is osteofibrous dysplasia?
A
- A rare form of fibrous dysplasia that primary affects Tibia
- confined to cortices
- usually younger children
- males> females
- location
- ant tibia
- Genetics
- Doesn’t have Gs alpha activating mutation cf fibrous dysplasia
- trisomy 7,8,12,22 reported
10
Q
What is the prognosis of osteofibrous dysplasia?
A
- lesions usually regress & don’t cause problems in adulthood
11
Q
What are the symptoms and signs of osteofibrous dysplasia?
A
- Asymptomatic
- painless swelling
- anterior/ anterolateral bowing of tibia
- pseudoarthrosis develops in 10-30%
OE
- local tenderness over tibia
12
Q
What radiographic features is seen in osteofibrous dysplasia?
A
- Anterior eccentric lytic lesions in a child -> tibial bowing
- usually diaphyseal
- no periosteal reaction
- confined to anterior cortex
- ddx includes adamantioma
13
Q
What is the histology in osteofibrous dysplasia?
A
- Similar to fibrous dysplasia except Osteoblastic rimming is present- see pic
14
Q
What is the tx of osteofibrous dysplasia
A
Non operative
-
Observation
- first line of tx- for most pts this alone
-
Bracing
- deformity significant and interfering w walking
Operative
-
Deformity correction w osteotomy
- rarely needed
- significant deformity
- preform after skeletal maturity
15
Q
What is Paget’s disease?
A
-
A condition of abnormal bone Remodelling
- original osseous tissue is reconstructed thru active interplay between excessive bone resorption and abnormal new bone formation
- Increase osteoclastic bone resorption is primarily cellular abnormality
- cause = slow virus infection
- paramyxovirus
- respiratory syncytial virus
- Peak incidence 5th decade
- common causcians
- males= females
- location
- monostotic/polyostotic
- femur, pelvis, tibia, skull, spine
16
Q
What are the genetics of Paget’s disease?
A
- Most spontaneous
- familial clusters 40% autosomal dominant transmission
- mutations - 4 found
- most important SQSTM1 - worse Paget’s
17
Q
What are the orthopaedic manifestations of Paget’s disease?
A
- Bone pain
- Long bone bowing
- fx - due to brittle bones- tend to be transverse
- Large joint OA
18
Q
What is the prognosis of Paget’s disease?
A
-
Paget’s sarcoma
- <1% will develop Paget’s sarcoma( 2ary sarcoma)
- Osteosarcoma is most common then fibrosarcoma & chondrosarcoma
- most common in pelvis, femur and humerus
- poor prognosis
- 5 yr survival for non mets Paget’s sarcoma is <5%
- tx with Chemo & wide surgical resection
19
Q
What is the classification of Paget’s disease?
A
- 3 phases
- Lytic- intense Osteoclast reabsorption
- Mixed- resorption/compensatory bone formation
- Sclerotic- osteoblastic bone formation
All 3 phases may coexist in same bone
20
Q
A
21
Q
What is the presentation of Paget’s disease?
A
-
Asymptomatic
- found incidentally
-
Pain
- stress fx
- increase vascularity and warmth
-
New onset of Pain and swelling
- 2ary sarcoma
- Cardiac Symptoms
- can pc- High output cardiac failure particularly if large/multiple lesions and pre-exisiting dimished cardiac function
22
Q
What is seen in radiographs with Paget’s disease?
A
- Coarsened trabeculae give bone a blastic appearance
- lytic phase
- blade of grass/flame shaped lucent advanced edge
- mixed- lytic and sclerotic w coarsened trabeculae
- sclerotic- bone enlargement w cortical thickening- see pic
- long bone bowing
- fx
- osteitis circumscripta- cotton wool exudates in skull
23
Q
What is seen in bone scan of Paget’s disease?
A
- Accurately marks site of disease
- intensely HOT in LYTIC and MIXED phase
- Less HOT in sclerotic phase
24
Q
What is seen in lab results of Paget’s disease?
A
- Elevated serum alk phosphatase
- elevated urinary hydroxyproline ( collagen breakdown)
- Increase urinary N telpeptide, alpha- C telopeptide and deoxypyridinoline
- Normal calcium levels
25
Q
What is seen in histology of Paget’s disease?
A
- Woven bone and irregular braod trabeculae with disorganised cement lines in a mosaic pattern
- numerous large osteoclasts w multiple nuclei per cell
26
Q
What is the tx of Paget’s disease?
A
Non operative
-
Observation and supportive tx
- asymptomatic pts
- physio, nsaids, oral analgesics
-
Bisphosphonates
- alendronate, risedronate oral -
inhibits oc and ob
* pamidronate- iv, inhibits only oc * **Calcitonin** * = Oc to shrink in size and decrease bone resorptive activity within minutes
Surgery
-
THR/TKR
- need to tx to reduce bleeding esp THR - not in lytic phase
- > incidence of suboptimal aligment 2ary to pagetoid bone highest in TKR
-
Metaphyseal osteotomy and plate fixation
- fx thru path bowing of long bones
- impending fx
27
Q
What is Histocytosis X or Langerhans cell histiocytosis?
A
- A spectrum of diseases of the reticuloendothelial system with one in three general presentations
- Eosinophilic granuloma (EG)- is a tumor like condition secondary to proliferation of histiocytes, usually a self limited lesion found in younger pts
- Hand-Schuller-Christian Disease (HSC)- chronic, disseminated form of bone & visceral lesions, aKA langerhans cell histocytosis w visceral involvment
- Letterer-Siwe disease- a fatal form that occurs in young children
29
Q
What is the prognosis of histocytosis X?
A
- Eosinophilic granuloma
- isloated involvment generally treatable
- spine lesions spontaneously resolve
- HSC
- prognosis depends on response to chemo
- worsening prognosis w increasing extraskeletal involvment
- LSD
- generally fatal in children <3 yrs
30
Q
What is the symptoms of eosinophilic granuloma?
A
- Pain and swelling in region of involvement
- localised/diffuse back pain
- HSC
- multiple skull lytic lesions- similar to MM
- diabetes insipidus
- exopthalmos
- visceral involvment- diffuse/ non specific adbo/chest pain
31
Q
What is seen on xrays of eosinophilic granuloma?
A
- Known as the great mimicker similar to
- osteomyelitis, lymphoma, fibrous dysplasia, Ewing’s sarcoma
-
Diaphyseal lesions
- well defined lytic/punched out- see pic
- cortex thinned/expanded/destroyed
- may have periosteal reaction
-
Metaphyseal lesions
- extend up to but not thru physis
- less central location cf diaphyseal lesions
-
Spine
- vertebra plana- flattened vertebra
- increased kyphosis
32
Q
What is seen on histology of eosinophilic granuloma?
A
-
Langerhans cells
- mononuclear histocyte like cells w oval nuclei w well defined round/ oval cytoplasm
- a prominent nuclear groove ( coffee bean nuclei) can be seen in most of the nuclei- blue arrow
33
Q
Describe the tx of eosinophilic granuloma?
A
Non operative
-
Observational
- a self limited process so can be tx by obs alone
-
Bracing
- prevent kyphosis of spine
- will correct deformity in 80% pts
- vertebral lesions general regain 50% height
- prevent kyphosis of spine
-
Low dose Radiation 600-800 cGy
- for lesions in spine that compromise stability
- effective most lesions
-
Chemotherapy
- Diffuse HSC
- methotrexate/vinblastine
- prognosis improved w less severe extraskeletal involvement
-
Corticosteriod injection
- isolated lesions, post currettage
Operative
-
Curettage and bone grafting
- Lesions that endanger articular surface or at risk of fx
-
Spinal deformity correction
- progressive spinal deformity refractory to bracing
- 10% will need op.
34
Q
What is Myositis Ossificans?
A
- A form of Heterotrophic Ossification that is the result of
- Direct trauma
- Intramuscular haematoma
- Most common location is Diaphysis of bone
- Must differentiate from tumours
-
Fibrodysplasia ossificans progressiva (FOP) is a rare subtype of HO - Stone man’s disease
- mutation of ACVR1 gene ( activin A type 1 receptor gene)
- progressive HO (muscles/fascia/tendons/lig/joint capsule) w great toe abnormality ( hallux varus/malformed MT
35
Q
What are the symptoms of myositis ossificans?
A
- Pain that decreases with time
- Size of mass that decreases with time
- O/E
- palpable mass
- restricted rom- see pic
36
Q
What is seen on xrays of myositis ossificans?
A
- Perpherial bone formation with central lucent area
- May appear as dotted vein pattern
38
Q
What is Melorheostosis?
A
-
Rare, Benign Painful devleopmental dysplasia of cortical bone. effecting the extremities charcterised by formation of Periosteal new bone formation
- usually before 40 yrs
- M=F
- lower extremities > upper
- Non hereditary
39
Q
What are the symptoms of Melorheostosis?
A
- Pain
- reduced ROM
- Joint contractures
O/E
- fibrosis of the skin w induration/ erytherma
- reduced rom
- painful hyperostoses
40
Q
What is seen on radiographs of Melorheostosis?
A
- Cortical Hyperostosis
- Dripping candle wax w dense hyperostosis that flows along the cortex of the bone
- Hyperostosis may flow across the joints
41
Q
What is seen on histology of Melorheostosis?
A
- Normal Haversian systems with enlarged bone trabeculae & without cellular atypia or mitotic figures
43
Q
What is heterophic ossification?
A
- Atypical formation of bone in extraskeletal tissues
- usually occurs spontaneously or following trauma
- within 2/12 of neurological ( brain) injury)
- most often found between muscle and joint capsule
44
Q
Where are the common locations of heterophic ossification?
A
-
post brain injury
- hip> elbow > shoulder>knee
- Elbow Ho > post brain trauma
- occurs on affected spastic side
- rarely in the knee
-
post spinal cord injury
- hip> knee>elbow>shoulder
- Hip flexors and Abductors >Extensors and adductors
- Medial aspect of knee
49
Q
What is HO seen on imaging?
A
- xrays
- ossification easy to visualise
- bony cortex= maturity
- trabecular pattern
- sharp demarcation from surrouding tissues
- USS
- for early dx of HO
- echogenic surfaces with posterior acoustic shadowing
- Bone scan
- triphasic for early dx
50
Q
what is seen labs results with HO?
A
- Elevated alkaline phosphatase
- Elevated CRP
- Elevated CK
- extent of muscle involvement
53
Q
what is tumoral calcinosis?
A
- Rare
- Calcium salts deposited in extra-capsular soft tissues
- more common in
- Females
- Afro-Caribbean
- typcially occurs around joints
- shoulders
- hips
- Unknown pathophysiology but thought to be due to abnormality of Phosphorus metabolism
56
Q
What seen on imaging of tumoral calcinosis?
A
xrays
- circular or oval well demarcated masses of calcium around joint
- direct involvement of bones/joint rare
Ct/MRI
- Demonstrate masses with fluid levels
Bone scan
- increase uptake in calcific masses
57
Q
What is the tx of tumoral calcinosis?
A
Non operative
- Observation
- for non symptomatic pts
Operative
-
Complete surgical excision
- for symptomatic lesions
- complete surgical resection to reduce chance of reocurrance
58
Q
What is this ?
A
- Bone infarct
59
Q
What is a bone infarct?
A
- Thought to be same spectrum as osteonecrosis
- occurs within Metaphysis or Diaphysis of long bones
- risk factors
- Trauma
- Sickle cell
- Connective tissue disorders
- Gaucher’s disease
- Steriod use
- Aetiology= Interuption of blodd supply by intrinsic/extrinsic factors
61
Q
What is seen on imaging of bone infarcts?
A
- Xrays
- Medullary lesion of sheet like central lucency surrounded by sclerosis with a serpiginous border
- “Smoke up the Chimney”
-
MRI
- Central signal remains of normal marrow- see pic
-
T2
- acute infarct may show ill-defined non-specific area of high signal
- intense inner ring of granulation tissue and a hypointense outer rong of sclerosis
-
Bone scan
- Cold in early phases
- hot in resorptive/revascualrisation phase
63
Q
What is focal fibrocartilaginous dysplasia?
A
- A Benign Dysplasia -> Unilateral varus of tibia
- Usually seen in infants/toddlers
- Aetiology and pathogenesis unknown
64
Q
What is the presentation of focal fibrocartilaginous dysplasia?
A
- Unilateral Tibial Vara
- Knee Hyperextension with lateral thrust
65
Q
What is seen on xray of focal fibrocartilaginous dysplasia?
A
- Abrupt varus at Metaphyseal- Diaphyseal junction
- Cortical sclerosis at Medial cortex
- Radiolucency may appear just proximal to area of cortical sclerosis corresponding to fibrocartilaginous tissue
66
Q
What is the histology of focal fibrocartilaginous dysplasia
A
- A prominent layer of collagenic fibrous tissue with thick dense fibrocartilagenous tissue
67
Q
What is the tx of focal fibrocartilaginous dysplasia?
A
Non operative
- Observation
- majority spontaneously correct beacuse of the normal proximal tibial physeal growth
Operative
- Deformity correction
- maybe necessary if the deformity progresses or fails to resolve during a period of observation or orthotic management
