MSK malignancy Flashcards
Which types of bone and surrounding tissue tumours are rare?
primary malignant bone tumours
tumours of soft tissue
Which is the most common tumour pathology of bone ?
bone mets
which sarcomas affect adolescents?
osteosarcoma
Ewing’s sarcoma
Give an example of a sarcoma whose incidence increases with age
chondrosarcoma
what is a sarcoma?
malignant tumour of connective tissue
think connection is when things ‘SAR COMing together’
what is a carcinoma?
malignant epithelial/endothelial tumour
Are sarcomas more common in males or females?
males
Are soft tissue tumours more common in males or females?
equal distribution between makes and females
what age group tends to get the most soft tissue tumours?
incidence increases with age - peaks at 64-80 yrs old
What features of a history are important in MSK tumours?
age = epidemiology
presenting complaint - mass, growing in size?, pain, loss of function, socrates
history of PC - duration of symptoms, full pain/mass history, how the issue came pt the pt’s attention, anything that makes it worse/better, lump in more than one site?
PMH
DH- drugs and drug history
FH
SH - current level of function? - affects treatment and epidemiology
What are the red flags for MSK tumours?
pain at rest pain at night lump present - tender, enlarging, deep to fascia and above 5cm in diameter loss of function neurological symptoms unwell/weight loss
What are the aspects of examination for MSK tumours?
look, feel, move
- look at the pt as a whole, look at all four limbs, how they walk, lumps, scars, transilluminescence
- feel - for masses, size, shape, painful, smooth, irregular, tethered to skin or deep tissues
- move - what function do they have when they move, range of motion, neurovascular status
What initial investigations are done for MSK tumours?
blood tests - FBC, U/E, Ca2+, ALP XR ultrasound CT MRI Technetium bone scan
If someone has widespread bone mets, what will happen to their calcium?
it will be high
What is a CT scan good for here?
assessing bone quality solid tumours staging using CT chest, abdo, pelvis if mets suspected 3D reconstruction of bony lesions helps plan for surgery
What is an MRI scan good for here?
reactive changes of soft tissue/ bone marrow
periosteal and endosteal reactions
skip lesions
can do whole body MRI to stage
what is a technetium bone scan good for?
assessing skeletal mets
can see how fast blood is flowing into a lesion, whether there is capillary dilation ie inflammation around a lesion, whether there is increased bone turnover
What is an XR good for here?
can look at the bone density, zone of transition, periosteal reaction
lytic or sclerotic (benign)
is the border well defined or irregular
can distinguish between benign and malignant
What are the characteristics of a malignant bone tumour on XR?
periosteal reaction
wide zone of transition (from abnormal bone to normal bone)
increased density
ill-defined lesion
What are the special signs of periosteal reactions seen on XR?
Codman’s Triangle
Sunburst appearance
Onion-skin appearance
Is the tumour likely to be benign or malignant with sunburst appearance?
malignant
In which cancers is the sunburst appearance seen?
osteosarcoma
Ewing’s
what is ultrasound scan good for here?
assessing soft tissues
can differentiate normal and abnormal and solid V. cystic
How is a technetium bone scan taken?
Inject the radioactive isotope and the gamma camera takes pictures at different times
what should you do if you suspect a primary bone or soft tissue sarcoma?
discuss the pt with MDT before proceeding with ANY invasive intervention
If a malignant process is found to be occurring, what is the next line of investigation?
biopsy
What are the principles of taking a biopsy for MSK tumours?
- needs to be done by the operating surgeon or consultant radiologist in the specialist centre where the operation will be carried out
- longitudinal incision in line with the planned incision for future surgical procedure
- shortest route to tumour, ie little soft tissue disturbance
- Access only one muscular compartment
- Ensure sample(s) is representative of tumour
- Meticulous Haemostasis (also, use a Tourniquet)
- Drain to be placed in line with Incision
- Send sample(s) to BOTH Histology and Microbiology
How is local staging done?
XR of the WHOLE bone
MRI to assess skip lesions
What scans are good for staging distally?
CT chest, abdo, pelvis
technetium bone scans
whole body MRI
how are MALIGNANT MSK tumours GRADED?
by the Enneking system
G0 - histologically benign
G1 - low grade malignant
G2 - high grade malignant
What does G0 mean in grading?
histologically benign, well differentiated, resembling the cell of origin, low mitotic count
What does G1 mean in grading?
low grade malignant moderate differentiation few mitosis local spread only low risk of mets
what does G2 mean in in grading?
high grade malignant
poorly differentiated - don’t look anything like their tissue of origin
frequent mitoses
high risk of mets
how are BENIGN MSK tumours GRADED?
Grade 1 - latent
grade 2 - active
grade 3 - aggressive
What does grade 1 benign mean?
LATENT
well defined margin
grows slowly and then stops
may heal spontaneously very low risk of recurrence
What does grade 2 benign mean?
ACTIVE
progressive growth limited by natural barriers
well defined margin but may expand and thin cortical bone
negligible recurrence after marginal resection
What does grade 3 benign mean?
AGGRESSIVE
growth not limited by natural barriers eg GCT
mets present in 5% of pts
high recurrence after marginal resection, so extended resection is needed
How are malignant MSK tumours STAGED?
TNM system
What does the prefix ‘rhabdomyo-‘ mean?
smooth muscle
What does the prefix of a tumour tell you?
the tissue of origin eg chondro-, osteo-, lipo-, rhabdomyo-
what does the suffix of a tumour tell you?
whether it is benign or malignant eg -oma, -carcinoma, -sarcoma, -blastoma
What happens if the tissue of origin is unclear?
the tumour will be described by its cellular appearance eg small cell carcinoma
If the tumour doesn’t resemble any kind of normal tissue, what is it called?
pleomorphic
Which type of tumours tend to permeate through bone, benign or malignant?
malignant
Which types of tumour tend to have a sclerotic rim, benign or malignant?
benign
What steps would you go through when describing an XR with a suspected tumour?
Name, DOB, time the XR was taken Describe radiographic view Describe anatomical location Epiphysis / metaphysis / diaphysis Bone forming / cartlilage forming Bone destruction / bone reaction Talk about the zone of transition
Name 3 types of bone cysts in children
Unicameral Bone Cyst (UBC)
Aneurysmal Bone Cyst (ABC)
Fibrous dysplasia
Name 3 types of destructive bone lesion in a young adult ie adolescent
osteosarcoma
Ewings
giant cell tumour
infection is a differential
Name 6 types of destructive lesion in over 50s
osteosarcoma chrondrosarcoma mets myeloma/lymphoma GCT
differential is infection
In which part of the bone is mets most likely to occur and why?
in the metaphysis as this is where there is anastamoses ie good blood supply to the bone
