tumours Flashcards
classification of bone tumours
WHO classification
- Cartilage forming
- bone forming
- fibrous
- non-matrix forming
Cartilage forming
Benign - osteochondromas (EXT gene), endochondromas (maffucis and ollier’s - malignant transformation)
Malignant - chondrosarcomas
Bone forming
Benign - osteoid osteoma and osteoblastoma
Malignant - osteosarcoma - pagets and radiation sarcoma
Fibrous
Benign - non-ossifying fibrom and fibrous dysplasia
Malignant - fibrosarcoma - resect and reconstruct
Non-matrix forming
Benign - UBC, Aneurysmal bone cyst, haemangioma, giant cell tumour, eosionphilic granuloma
malignant - Ewing’s sarcoma, chordoma
xray findings for tumours
- zone of transition
- matrix
- size of tumour in relation to bone
- codman’s triangle - reactive bone elevating the periosteum
- sunray - periosteal reaction - rapid bone growth
- onion-skinning - multiple layers of periosteal bone formation - EWING’s sarcoma
principles of biopsy
- centre performing definitive procedure
- intracompartmental
- respect NV structures
- drains brought out inline with future incisions
- meticulous haemostasis
- biopsy periphery instead of necrotic
- longitudinal incisions - positioned so tract can be removed
types of biopsy
- percutaneous biopsy - tru-cut
- incisional - only if percutaneous is non-diagnostic
- excisional biopsy- benign lesions confirmed on imaging or small superficial tumours where excision doesnt interfere with further surgery
Staging systems
definition or staging and grading
staging - describes the size, location and spread of a tumour
grading - histological appearance of cells - how abnormal
Enneking/ musculoskeletal tumour society uses grade, location and presence/ abscence of metastasis
GRADE
- low grade = stage I
- high grade = stage II
- metastatic = stage III
LOCATION
- intracompartmental = A
- Extracompartmental = B
management of suspected tumour
Principles
1. rule out infection
2. stage tumour
3. refer to oncology and bone tumour unit
Hx
- malignancy
- constitutional symptoms
- function
- prior infection/ current sinuses
Biochemical
- FBC, inflammatory markers, UEs, LFT, Bone profile (hypercalcaemia), TFTs
- tumour markers - PSA, myelomma screen (electrophoresis), CAE, CA-125
Imaging
- local staging - MRI to look for soft tissue involvement
- distant staging - CT TAP
principles of tumour surgery
- save life
- save limb
- save function
What are the resection margins?
Intra-lesional
* passes through tumour
* macroscopic tumour remains
Marginal
* tumour excised with intact pseudocapsule
* microscopic tumour may remain
Wide margin
* tumour excised with cuff of normal tissue
* risk of remaining microscopic skip lesions
Radical margin
* entire compartment excised
what is a sarcoma?
malignant tumours arising from connective tissue - embryonic mesodermal layer
- Definition
- management of osteosarcoma?
bone forming malignant tumour
- retinoblastoma
- metaphysis infiltration - destructive and sclerotic
Treatment
- neoadjunctive chemotherapy
- surgery
- adjunctive chemotherapy
good response to chemo is >90% necrosis
- Definition
- management of chondrosarcoma?
malignant primary bone tumour consisting of malignant chondrocytes
- most common in pelvis (25%), femur and humerus
- risk of transformation from MHE, ollier’s and maffucci’s disease
treatment:
wide excision
NOT chemo or radio
- definition of giant cell tumour
- management of giant cell tumours?
destructive, locally aggressive lesion at the epiphysis of long bones
- distal femur, proximal tibia and distal radius
- lung mets
treatment
- denosumab - RANKL inhibitor
- curretage and bone graft
what is this?
non-ossifying fibroma
- soap bubbles
- incidental finding
- lucency and sclerotic margin
Fibrous dysplasia
monostotic fibro-osseous lesion
- shepherd’s crook deformity of prox femur - multiple fractures
- well demarcated, fusiform expansion, ground glass calcification and cortical thinning
Polyostotic fibrous dysplasia - McCune Albright syndrome
- precocious pubertu
- jagged cafe au lait spots
- spots are unilateral and don’t cross midline
treatment
- bisphosphonates - polyostic
- immobilise/ fix fractures
UBC - unicameral bone cyst- definition and management
simple bone cyst - serous fluid filled
managment
- observation - small lesion - rexray
- immobilisation - humeral pathological fracture - fracture encourages healing
- currettage, bone graft and fixation - femoral fracture
ABC - definition and management
benign reactive bone lesions
- typically occur in femur and tibia
- fluid levels of mri
treatment
- curretage and bone graft - no fracture - high recurrence - 50%
- observe or fix if fracture
Ewing’s sarcoma - definition and management
malignant, small round blue cell bone neoplasia
- metaphysis/ diaphysis - femur/ tibia and humerus
- xray - onion peel - periosteal reaction
- pulmonary mets
management
- chemotherapy
- wide excision
- radiotherapy
