Chrondrogenic tumours Flashcards
Enchondromas periosteal chondromas Osteochondromas & mutliple hereditary exostois Chondroblastoma Chondromyxoid fibroma Chondrosarcoma
1
Q
what is an enchondroma?
A
- A Benign chrondrogenic tumour- 2nd most common
- composed of Hyaline cartilage
- caused by abnormality in chondrocyte function in the physis
- M=F
- most common 20-50 yrs
- usually in medullary canal in diaphysis and metaphysis
- most common in hand 60%
-
location
- distal femur, proximal humerus,tibia
- rare in spine/pelvis
2
Q
What is the pathophysioogy of enchondroma?
A
- enchondromas represent incomplete endochondral ossification
- chondroblasts and fragments of epiphyseal cartilage escape from the physis, displace into the metaphysis and proliferate there
3
Q
Name associated conditions of enchondromas?
A
- Solitary enchondromas
-
Ollier’s disease
- multiple enchondromatis
- no genetic predisposition
- skeletal dysplasia with failure of normal endochondral ossification
- enchondromas throughout the metaphyses and diaphyses of long bones
- involved bones are dysplastic, with shortening and bowing
- risk of malignant transformation <30%
-
Maffucci syndrome
- sporadic inheritance
- multiple enchondromas & soft tissue angiomas
- risk of malignancy 100%
- increased risk of visceral malignancy
4
Q
Can you describe the enneking staging of benign lesions?
A
- Grade 1- Latent lesion-= enchondroma, non ossfiying fibroma
- Grade 2- Active lesion =ABC/UBC/Chondroblastoma
- Grade 3- Aggressive lesion = GCT
5
Q
Describe the symptoms and signs of enchondromas?
A
Symptoms
- asymptomatic- found incidentially- tibia
- pathologcial fx- hand
-
Pain - uncommon
- most chondrosarcomas have non mechanical pain
Signs
- Angular deformity and shortening
- blusih angiomas of maffucci
6
Q
What is seen on xrays of enchondromas?
A
- pop corn stippled calcification & rings
- bone expansion
- Lytic in hand
- in Maffucci = angiomas are visible as calcified phleboliths
7
Q
How are chondrosarcomas different from enchondromas?
A
- unlike enchondromas, chondrosarcomas display
- cortical thickening and destruction
- endosteal erosions and scalloping >50% of the width of the cortex
are larger (>5cm)
8
Q
Describe the histology in enchondromas?
A
- hypocellular with bland, mature hyaline cartilage (blue balls of cartilage) separated by normal marrow
9
Q
Describe the tx of enchondromas?
A
- non operative
-
observation
- majority
- with serial xrays in 3-6months for 1-2 years
- long term FU with multiple enchondromas
-
observation
-
Surgery
-
intralesional curettage & bone graft
- lesions that show any change in lesion
-
immobilisation, currettage & bone graft
- path fx
- immobilisatio until union then currettage & BG
-
intralesional curettage & bone graft
10
Q
What is periosteal chondroma?
A
- A rare type of chondroma - benign
- occurs on surface of long bones
- under periosteum of distal femur,prox humerus and prox femur
- 59% prox humerus
- 10-20 yrs old
11
Q
what are the symtpoms of periosteal enchondromas?
A
-
Pain
- 2ary to irriation from tendons
12
Q
What is seen on radiographs with periosteal enchondromas?
A
- saucerization of underlying bone
- punctate mineralisation in 1/3
- well demarcated, shallow cortical defects
13
Q
What is seen on histology of periosteal enchondromas?
A
- Bland hyaline cartilage
- small chondroid cells in lacunar spaces
14
Q
What is the tx of periosteal enchondromas?
A
- Operative
- marginal excision including underlying cortex
- if symptoms intereferring with function
- lesion with reoccurif cartilage is left behind
15
Q
What is an osteochondroma & multiple hereditary exostosis?
A
- A Benign chrondrogenic lesion derived from aberrant cartilage from the periochondral ring that may take the form of
- solitary osteochondroma
- Multiple hereditary exostosis ( MHE)
- Most common Benign bone tumour
- Many asymptomatic
- common adolescents/young adults
- location on surface of bones, often at sites of tendon insertions
- knee
- prox femur
- prox humerus
- sugungal exostosis- at hallux
- Autosomal Dominant
- Mutation in EXT gene affects prehypertrophic chondrocytes of growth plate
16
Q
What are the associated conditions of osteochondroma & multiple hereditary exostosis?
A
-
Secondary Chondrosarcomas
- a malignant condition that results from malignant transformation of solitary osteochondromas or MHE
- occurs older pts - 50 yrs
- most common location is the pelvis
17
Q
What is the prognosis of osteochondroma & multiple hereditary exostosis?
A
- Risk of malignant change
- <1% solitary osteochondromas
- 5-10% in multiple hereditary exostosis develop secondary chondrosarcomas
18
Q
Define multiple hereditary extosis
A
- Disorder characterised by multiple osteochondromas
- mutation affects the prehypertrophic chondrocytes of the physis
- Autosomal Dominant
- mutations in EXT1 ,EXT2, EXT 3 genes = tumour suppressor genes
-
ext1 individuals > severe presentation cf EXT 2 mutations
- higher rate of osteosarcomas
- more exostoses
- more limb malignment
19
Q
What is the prognosis of MHE?
A
- 5-10% malignant change to chondrosarcomas
- proximal lesions more likely to undergo malignant transformation than distal lesions
20
Q
What are the symptoms of osteochondromas?
A
- most asymptomatic
- painless mass
- NV compromise
- mechanical symptoms
21
Q
What are the symptoms of MHE?
A
Limb deformities
- femoral shortening & LLD
- coxa Valga
- knee valgus- shortened fibular, patella dislocation
- ankle valgus- shortened fibular
- upper limb- ulna shortening, radial head dislocation/radial bowing
- nay increase in acute apain should raise suspicion of malignancy
22
Q
What is seen on radiographs with osteochondromas & multiple hereditary exostosis?
A
- Sessile ( broad base)
- Pedunculated ( narrow stalk)
- found on surface of bones
- >malignancy risk in sessile lesions
- pedunculated point away from joint
- cortex of lesion continous w cortex of native bone
- medullary canal of lesion continous w medullary cavity of native bone
23
Q
What is the histology of osteochondroma & multiple hereditary exostosis?
A
- similar to normal physis with
- cartilage cap consisting of hyaline cartilage
- normal primary trabeculae
- linear clusters of active chondrocytes
- may have thin cartilage cap covering the lesion
29
Q
Define chondroblastoma?
A
- A benign chondrogenic lesion
- differs to GCT by chondroid matrix
- 2:1 male/female
- most pts <25yrs
- location= Epiphyseal lesion in young pts
- apophysis/ distal femur/ prox tibia/ prx humerus/prox femur
- Typically epiphyseal but may cross Physis
- chromosome abnormalities 5/8
32
Q
what is seen on xrays with chondroblastoma?
A
- Well circumscribed epiphyseal lytic lesion- thin rim of sclerotic bone that is sharply demarcated from normal medullary cavity
- lesions often cross physis into metaphysis
- cortical expansion present
- soft tissue expansion rare
33
Q
What is the DDX of the radiograph?
A
- Giant cell tumour
- chondroblastoma
- clear cell chondrosarcoma
- Osteomyelitis
34
Q
What is seen on histology in chondroblastoma?
A
- Chondroblastoma arranged in Cobblestones or dhicken wire- see pic
- occasional multinucleated giant cells
- scattered multinucleated giant cells with focal areas of chondroid matrix
36
Q
Describe chondromyxoid fibroma?
A
- A rare
- Benign chondrogenic lesion
- characterised by variable amounts of chondroid, fibromatoid and myxoid elements
- > in males
- most common in 2nd/3rd decades of life
- location
- long bones- tibia, distal femur, pelvis ot hands
- Mutations of chromosome 6 position q13
- may reocur in 20-30% cases
38
Q
What is seen on xrays with chondromyxoid fibroma?
A
- Lytic, eccentric metaphyseal lesion
- scalloped and sclerotic rim
- calcifications RARE
39
Q
What is seen on mri with chondromyxoid fibroma?
A
- T1 weighted low signal
- T2 weighted high signal
40
Q
What is seen with histology with chondromyxoid fibroma?
A
- Lobules of fibromyxoid tissue
- hyperchromatic nuclei
- lobules contain spindle shaped cells/stellate shaped
- high power stellate cells seen
43
Q
What is Chondrosarcoma?
A
- A Malignant chondrogenic lesion that can occur in 2 forms
-
primary chondrosarcoma
- low grade,high grade
- clear cell chondrosarcoma
- mesenchymal chondrosarcoma
-
Secondary chondrosarcoma
- arises from benign cartilage lesions
- osteochondromas
- Mutliple hereditary exostosis
- Enchondromas (1% transformation)
- Ollier’s disease (20-45% transformation)
- Maffucci ( 100% transformation)
- arises from benign cartilage lesions
-
primary chondrosarcoma
45
Q
Describe clear cell chondrosarcomas?
A
- malignant immature cartilagenous toumour
- accounts for
- common 30-040 yrs
- insidious onset of pain
- epiphyseal in location ( ddx from GCT ( giant cells) /chondroblastoma ( young pts)
- locally destructive with potential to metastatsize
47
Q
What does a pt with chondrosarcomas present with?
A
- Pain - most common
- slow growing mass/ bladder or bowel obstruction ( mass effect in pelvis)
- 50% of de-differentiated chondrosarcomas pc pathological fracture
48
Q
What is seen on xrays in a pt with chondrosarcomas?
A
- Lytic or blastic reactive thicknening of cortex
- low grade
- similar appearance to enchondroma w additional cortical thickneing/expansion
- high grade
- cortical destruction & a soft tissue mass
- intra-lesional ‘popcorn mineralisation’
- MRI- useful ti determine cortical destruction
- bone scan- v hot
49
Q
Describe the histology of chondrosarcomas?
A
- No needle biopsy as difficulties in diagnosis
- low grade
- few mitotic figures with bland histologic appearance
- enlarged chondrocytes w plump nucleated lacunae - see pic
- high grade
- hypercellular stroma w blue balls of cartilage lesion which permeate the bone traecular
- De differentitated- high level of spindle cells
