Bone and Soft Tissue Tumours Flashcards
Most common primary bone tumour in young
Osteosarcoma
Most common primary bone tumour in older
Myeloma
Difference between pain in bone tumours and benign tumours
Bone
- Pain is activity related
- progressive pain at night and rest
Benign
- may be activity related if large enough to weaken bone
- Osteoid osteoma pain - dull pain that escalates to severe pain at night
other than pain how else can bone tumours present
swelling
pathological fracture
mass
incidental abnormal x-ray
how to exam for suspected bone tumour
general health measure mass location, shape, consistency, mobility, tenderness of mass local temperature neuro-vascular deficits
Investigations for suspected bone tumour
X-ray - most useful
CT - for assessing ossification and calcification, staging
MRI - accurate for limits of disease
Isotope bone scan - staging for skeletal mets
Angiography -
PET - response to chemo
difference in x-rays for inactive and active tumours
Inactive
- clear margins
- surrounding rim of reactive bone
- cortical expansion possible in aggressive benign lesions
Active
- less well defined zone of transition between lesion and normal bone
- Cortical destruction (means malignancy)
- New bone formation (occurs when the lesion destroys the cortex)
- Codman’s triangle
- Onion skinning
- Sunburst pattern
What work-up needs to be done prior to biopsy of bone tumour
Bloods X-ray of affected limb and chest MRI of lesion Bone scan CT chest, abdo, pelvis
Cardinal features of malignant primary bone tumour
Increasing and unexplained pain Deep-seated boring nature Night pain Difficulty weight bearing Deep swelling
Examples of malignant primary bone tumours
Osteosarcoma
Ewing’s sarcoma
Chondrosarcoma
Typical presentation of primary and secondary osteosarcoma
Adolescents arising in metaphases of long bone esp. around the knee
Secondary OS common in bone affected by Paget’s disease or irradiation
Clinical Features of Osteosarcoma
Pain - increasing, analgesics become ineffective, unexplained, deep boring ache, NIGHT
Loss of Function - limp, reduced joint movement, stiff back
Swelling - diffuse, near end of long bone, rapid enlargement, warm, venous congestion, pressure effects
Pathological Fracture
Joint Effusion
Deformity
Neurovascular Effects
Systemic Effects of Neoplasia
Investigation of choice for osteosarcoma
MRI - shows bone destruction and new bone formation and determines resection margins
Good for showing
- interosseous and extraosseus extent of tumour
- skip mets
- joint involvement
- epiphyseal extension
Treatment of osteosarcoma
Resection + Chemotherapy
What is Ewing’s sarcoma and what is its typical presentation
Malignant round cell tumour of long bones (typically diaphysis) and limb girdles
Usually in adolescents
t11:22 chromosomal translocation common
Radiographic findings in ewings sarcoma
(MRI helpful)
- Bone destruction
- Concentric layers of new bone formation (onion skin)
- A soft tissue mass
Treatment of ES
Chemo + resection and limb salvage therapy
or RT
Prognosis of ES
22% 5 year recurrence rate if mets at diagnosis
55% 5 year recurrence rate if no mets at diagnosis
Typical presentation of chondrosarcoma
Benign but aggressive tumour
Associated with pain or a lump
Presents in the axial skeleton of the middle aged
Investigations for chondrosarcoma
Radiograph - popcorn calcification
CT/MRI - define tumour extent
Treatment of chondrosarcoma
Excision (chemo nor RT work)
Suspicious signs of a soft tissue tumour
Tumours deeper than deep fascia
Subcutaneous tumours >5cm
Rapid growth
Hard, craggy, fixed, no distinct margins
Non-tender to palpation but deep ache, worse at night
BUT may be painless
Recurrence after previous excision
Most common sites of secondary bone tumours (most - least)
Vertebrae Proximal Femur Pelvis Ribs Sternum Skull
7 commonest primary cancers which metastasise to bone
- Lung (smoker, CXR, sputum cytology)
- Breast
- Prostate (osteosclerotic 2o), PR, PSA
- Kidney (solitary, vascular)
- Thyroid (esp. follicular ca)
- GI tract (FOB, endoscopy, markers)
- Melanoma
Prognosis after pathological fracture
~50% survive >6m
~30% survive >1y
Breast + soft tissue mets ~1-2y survival
Prevention of pathological fracture
Early chemo or Deep X-ray therapy
Prophylactic Internal Fixation (if lytic lesion + increasing pain and/or:
- >2.5cm diameter
- >50% cortical destruction
Bone cement
Embolisation - esp. renal or thyroid (wait 48h before surgery)
What system is used for fracture risk assessment
Mirel’s Scoring System
- Maximum score = 12
- Score >8 prophylactic fixation is recommended prior to RT
difference between osteolytic and osteoblastic lesions
OL = tumour causes bone breakdown / thinning, calcium released from bone into bloodstream, lucencies, common in multiple myeloma
OB = increased bone production, thickening, rigid, inflexible bone formed, common in prostate cancer
What scores 1 in Mirel’s
Site - UL
Pain - mild
Lesion - blastic
Size - <1/3
What scores 2 in Mirel’s
Site - LL
Pain - moderate
Lesion - mixed
Size - 1/3-2/3
What scores 3 in Mirel’s
Site - Peritrochanter
Pain - Functional
Lesion - lytic
Size >2/3
Commonest soft tissue tumour
lipoma
Presentation of lipoma
Painless lump which increases in size
Deep to deep fascia
Mass >5cm
Can become painful in malignancy
Investigation of soft tissue tumour
MRI followed by needle biopsy
Treatment of STTs
Excision with wide margins followed by RT
chemo generally insensitive in adult STTs
most common metastasise in STTs
to Lungs (haematogenous spread)
