neoblastic bone disease Flashcards
tumour in popliteal fossa- why would this need an above knee amputation
want curative intent - cant just do excision, because tumour wraps itself around blood vessels and nerves in that area
epidemiology of bone tumours
very rare
can be benign/malignant
much less common than lung ca
primary malignant bone tumours more common in young adults and children
commenst malignant bone tumour is metastatic
site predilecation of bone tumours
osteosarcoma - around knee is most common
different tumours have different site and age predilection
clinical presentation of bone tumour dx
pain
swelling
deformity
pathological fracture
hx of bone tumour
age
site
duration
hx of trauma - can be misleading
multiple lesions - more likely metastatic or involve marrow like lymphoma
associated disease - wouldnt usually dx osteosarcoma in old, but if prev radiotherapy there, or Pagets disease consider it
ix for bone tumour
XR
* site, size, margin
* solitary/multiple
* soft tissue extension - feature of malignancy
* associated disease/fracture
biopsy
if suspect - refer quickly to specialist cenytre
where is the lesion
femur metaphysis
describe this lesion
lytic - destroyed the cortex
extend to soft tissue
biopsy for bone tumour
needle biopsy under radiological guidance with Jamshidi needle
+- US of CT guidance
open biopsy for sclerotic or inaccessible lesions only (ie if very bony and cant get needle in)
imprint (cytology) preparation - get dx in hrs about whether have representative tissue and whether benign/malignant
describe this bone biopsy
some pre-existing host bone
some changes in marrow
it is malignant - no normal marrow tissue, trabecular bone is irregular, cartilage is in marrow. So whatever is goung on iss infiltrating bone
benign conditions that mimic bone tumours
fibrous dysplasia
metaphyseal fibrois cortical defect/non-ossifying fibroma
reparative giant cell granuloma
ossifying fibroma
simple bone cyst
summarise fibrous dysplasia
same bones and age as osteosarcoma
- > female
- mono-ostotic > polyostotic
- 1st 3yr of life
- site - any bone, ribs, prox femur commonest
- XR - soap bubble osteolysis
polyostotic disease associated with endocrine problems, and rough border cafe au lait spots (McCune Albright syndrome)
<1% malignant transformation
somatic mutation in guanine-nucleotide binding protein (G-protein) (GNAS mutation chr 20q13)
XR for fibrodysplasia
soap bubble osteolysis
>1 bone
whereas osteosarcoma more likely one bone (unless met)
histology of fibrodysplasia
marrow replaced by fibrous stroma
rounded and curved trabecular bone
Rx of fibrodysplasia
can excise with a very small margin
no chemo
sheperd’s crook deformity in fibrous dysplasia
when fibrodysplasia happens in femoral head
bone weak and cystic -> microfractures
benign bone tumours
cartilaginous differentiation
* osteochondroma
* enchondroma
* chondroblastoma
bone forming
* osteoid osteoma
* osteoblastoma
* osteoma
osteochondroma commonest sites
end of long bone
top of humerus
around knee
pathology of osteochondroma
mimic tubular bone
have cartilaginous surface overling cortical and trabecular bone
histology of osteochrondroma
cartilage on surface
bone underneath
common sites for enchondroma
most in hands, some in feet
much less in long bones
definition of enchondroma
proliferation of cartilige within bone
XR of enchondroma
here in finger with pathological fracture
Type of lesion in this enchondroma
popcorn calcification
Describe this pathology of enchondroma
well circumscribed
is this benign or malignant
borderline considered to benign, but locally aggressive
well demarcated
eroded through cortex but hasnt burst through articular surface
haemorrhage looks malignant
Summarise giant cell tumours
borderline malignancy
site - epiphysis with metaphyseal extension
age - 20-30yrs
>female
- XR - lytic
- histology - osteoclasts on a background of spindle/ovioid cells
locally aggressive, can recur, can met to lungs
Mx of giant cell tumour
excise with limited margin
site predisposition for giant cell tumour
made of osteoclast giant cells
tumour cells are the stromal cells
site - end of long bone, most around knee
histology of giant cell tumour
sheets of osteoclast giant cell
Site predeliction for osteosarcoma
if older - jaw
most - lower femur/upper tibia
end of long bones
what is codmans triangle
sclerotic and lytic lesion gone into the soft tissue
pushed the periosteium up
-> forming triangle called Codman’s triangle
histopath of osteosarcoma
malignant bone
mesenchymal stroma
malignant cartilage
too many cells - osteosarcoma, looser myxoid area, and disordered bone
touch preparation for osteosarcoma
malignant cells produce alkaline phosphtase (bone cells use this to mineralise bone)
stain for this in core biopsy
where is this lesion
arm
tumour coming off the ulner into the soft tissue
describe this
humerus
white glistening tumour
lifted the periostium
some benign here but some malignant
chondrosarcoma because white, not as haemorrhagic as osteosarcoma
site prediliction from chondrosarcoma
most in pelvis
end of long bone
histology for chondrosarcoma
cartilaginous tumour
malignant cell in matrix
atypical chondrocytes (usually purple/blue)
site prediliction for ewing’s sacoma
pelvis
diaphysis of long bone
histology of ewings sarcoma
small round blue cell tumour
what do you have to exclude and how when dx ewings sarcoma
immunostaining
Ewings will be +ve for MIC2
ddx of spindle cell tumour
ddx of myxoid tumours
ddx of pleomorphic tumour
histology of synovial sarcoma
epithelioid area
spindle area
do immuno
diagnostic technique for soft tissue tumour
soft tissue sarcoma - tumour specific chr translocations
Px factors for soft tissue sarcoma
staging of soft tissue sarcoma
vascular invasion
pleomorphic tumour in blood vessels on way to lungs
macroscopic Ewing’s tumour
