Tumours of MSK system Flashcards
Epidemiology of bone tumours
Sarcoma of Bone account for 0.2% of all malignancies
Approx 500 diagnosed in the UK every year
However represent 4% of all malignancies in Children <14 years
Slight higher incidence in males (13:10)
Approx 3275 new cases per year in UK
Almost equal distribution between Males and Females (51:49)
Typical patient history for bone tumour
Presenting Complaint:
?Mass
?Pain
?Loss of Function
History of Presenting Complaint:
Duration of symptoms, including full Pain / Mass history
How issue came to patient’s attention
Past Medical History and Medication History
Family History
Social History – what is their current level of function?
Red flag signs in history
Rest pain
Night pain
Lump present – tender, enlarging, deep to fascia, above 5cm in diameter
Loss of function
Neurological symptoms
Unwell / Weight loss
Examination of patient
Look, Feel, Move
Assess function of a joint/limb:
Range of motion
Neurovascular status
Assess any masses
Scars
Skin lesions
sensations
Reflexes
Initial investigations
Blood tests – FBC, U+E, Ca2+, Alk Phos
Plain Xrays
Ultrasound
CT Scan
MRI Scan
Bone scan
Raised CRP and ESR
Urine
CT scan and tumours
Better for assessing bone quality, as well as solid tumours
Staging CT of Chest / Abdo / Pelvis essential if suspect metastases
MRI scan
Better for assessing reactive changes of soft tissue / bone marrow
Recent studies assessed full-body MRI to look for metastases
T1 imaging: anatomy
T2 imaging: pathology
Soft tissue masses
Skip lesions
Bone scan
Better for assessing reactive changes of soft tissue / bone marrow
Recent studies assessed full-body MRI to look for metastases
Plain x ray
Look to see what the lesion is doing to the bone and vise-versa
Definition / Bone density / Zone of Transition / Periosteal reaction
Osteoblastoma (looks dark) vs Osteosarcoma (looks bright white)
Plain x ray can show the location of the tumour in the bone… what are the locations in bone?
Epiphysis
Physis
Metaphysis
Diaphysis
Central/Cortical
A plain x ray shows the zone of transition what are they
Narrow - good
Wide - bad
Plain x rays can show the matrix, what is a matrix
Represents the extracellular matrix produced by tumor cells
Depends upon cellular lineage of progenitor cells
Fibrous – ground glass
Osteoid – Cumulus cloud
Chondroid – Popcorn
Plain x ray can show cortical involvement such as
Scalloping
Cortical thinning
Expansile
Ultrasound
Chepa and quick
Real time assessment
Differential normal vs abnormal, solid vs cystic
Staging: Grading of Malignant Tumours
Enneking system:
G0 = Histologically Benign
Well Differentiated i.e. resemble cell of origin
Low mitotic count
G1 = Low Grade Malignant
Moderate differentiation; Few mitoses
Local spread only. Low risk of metastasis
G2 = High Grade Malignant
Poorly differentiated; Frequent mitoses
High risk of metastasis
Enneking classification Grade 1
Latent
Well defined margin. Grows slowly then stops
May heal spontaneously and very low risk of recurrence
Enneking classification Grade 2
Active
Progressive growth limited by natural barriers
Well defined margin but may expand and thin cortical bone (e.g. ABC)
Negligible recurrence after marginal resection
Enneking classification Grade 3
Aggressive
Growth not limited by natural barriers (e.g. GCT)
Metastasis present in 5% patients
High recurrence following marginal resection (extended resection therefore needed)
Enneking classification: T1 AND T2
T1 - intracompartmental
T2 - extracompartmental
Guide to naming tumours prefix
Osteo… = Bone
Chondro… = Cartilage
Rhabdomyo… = Skeletal Muscle
Lipo… = Fat
Guide to naming tumours suffix
oma = Benign tumour
…sarcoma = Malignant connective tissue tumour
…carcinoma = Malignant epithelial/endothelial tumour
…blastoma = (Malignant) Tumour of embryonic cells
Outliers to naming tumours
Tumours may have an eponymous name (e.g. Ewing’s)
If the Tissue of Origin is unclear, the tumour may be described by its cellular appearance
Or, especially in soft tissue sarcoma, may come under the term
Where do bone tumours present
Osteosarcoma - knee (distal femur, proximal tibia)
Parosteal osteosarcoma - distal femur (posterior cortex)
Chondrosarcoma – pelvis
Giant cell tumors – knee
Chordoma – sacrum
Adamantinoma - tibia
Bone cysts usually found in children
Unicameral Bone Cyst (UBC)
Aneurysmal Bone Cyst (ABC)
Fibrous dysplasia
Eosinophlic granuloma (EG)
Intra-osseous lipoma (rare
Destructive lesions in young adults
Osteosarcoma
Ewings
Infection
Giant Cell Tumour (GCT)
ABC
Destructive lesions in those >50
Osteosarcoma
Chondrosarcoma
Metastasis
Myeloma/Lymphoma
Giant cell tumour
Infection
Bone Tumours
Benign
Osteoid Osteoma
Osteoblastoma
Osteochondroma
Malignant
Osteosarcoma
Fibrous tumours
Benign
Fibrous Dysplasia
Non-ossifying Fibroma
Malignant
Fibrosarcoma
Cartilage tumours
Benign
Enchondroma
Chondroblastoma
Malignant
Chondrosarcoma
Cystic tumours
Unicameral bone cyst
Aneurysmal bone cyst