Bone and Soft Tissue Tumours Flashcards
What are suspicious clinical features which indicate there could be a malignant tumour?
- Pathological Fractures
-
Bony swellings - Hard, fixed, craggy surface, indistinct margins
- Deep tumour (of any size) or Subcutaneous tumours > 5cm
- Non-mechanical bone pain - Non-tender, but assoc. with deep ache, esp. WORSE AT NIGHT
- Recurred after previous excision
What investigations would you perform if you suspected a bone tumour?
Complete work up
- Bloods
- X-rays of affected Limb & Chest
- MRI of lesion
- Bone Scan
- CT Chest, abdo & pelvis
What features on an x-ray would suggest an inactive bone lesion?
- Clear margins
- Surrounding rim of reactive bone
What features on an X-ray would suggest an aggressive bone lesion?
- Less well defined margins - between normal and abnormal bone
- Cortical destruction ⇒ malignancy
- Periosteal reactive new bone growth - occurs when the lesion destroys the cortex
- Codman’s triangle
- Onion-skinning
- Sunburst pattern
What can be determined using CT scan when investigating bone tumours?
- Assessing ossification and calcification
- Integrity of cortex
- Best for assessing nidus in osteoid osteoma
What can be determined using an Isotope bone scan when investigating bone tumours?
- Staging for skeletal metastasis
-
Multiple lesions
- Osteochondroma
- Enchondroma
- Fibrous Dysplasia + histiocytosis
- Uptake from benign lesions
What can be determined when using an MRI Scan when investigating bone/soft tissue tumours?
- Size, extent, anatomical relationships
- Accurate for measuring limits of disease - within and outside bone
- Specific - Lipoma, haemangioma, haematoma or PVNS.
- Non-specific - benign vs. malignant
What is one of the main uses of a PET scans for bone/soft tissue tissue tumours?
Response to chemotherapy
What is an osteosarcoma?
- Aggressive primary malignant neoplasm - 2nd most common to multiple myeloma
- Arises from primitive transformed cells of mesenchymal origin
- Produces malignant osteoid
Who does osteosarcoma most commonly affect?
- Adolescents - age 10-20 yrs - most common primary malignant tumour in Children
- Males>Females
- Those with Paget’s Disease
Where does osteosarcoma most commonly affect?
- Distal femur > proximal tibia > proximal humerus > proximal femur > distal tibia
What are the clinical features of osteosarcoma?
- Pain - progressive, deep seated, boring, WORSE AT NIGHT
- Deep swelling - near end of long bone, warmth over site + venous congestion
- Loss of function
- Limp/difficulty weight bearing
- Pathological fracture
- Systemic - Malaise, Fatigue, WL
What investigations would you do to investigate for suspected osteosarcoma?
- X-rays - Codman’s triangle, sunburst spiculation, mixed sclerotic/lytic lesion with indistinct margins
- MRI Scan - INVESTIGATION OF CHOICE
- HRCT Scan - chest mets
How would you treat osteosarcoma?
- Chemotherapy
-
Surgery
- Limb salvage possible for most cases
- Consider neurovascular involvement
- Pathological fractures
- Poorly performed biopsy
- Radiotherapy
What are the most common types of cancer to cause bone metastases?
Try to list in order of most common to least common
- LUNG
- BREAST
- PROSTATE
- KIDNEY
- THYROID
- GI TRACT
- MELANOMA
What scoring system can you use to assess risk of pathological fracture?
Mirel’s Scoring System
What is Codman’s Triangle?
Periosteum does not have time to ossify with shells of new bone (e.g. as seen in single layer and mulitlayered periosteal reaction), so only the edge of the raised periosteum will ossify
On an X-ray, what is onion skinning?
Multiple concentric parallel layers of new bone adjacent to the cortex, reminiscent of the layers on an onion.
On an X-ray, what is a sunburst pattern?
Periosteal reaction giving rise to Sunburst appearance; occurs when the lesion grows too fast and the periosteum does not have enough time to lay down a new layer
