Unknown origin tumours Flashcards
Metastatic bone disease Giant cell tumour ewing's tumour Adamantioma
1
Q
Describe metastatic cancer of bone?
A
- The commonest reason for a destructive bone lesion in adults
- cancers that spread to bone
- breast
- Lung
- thyroid
- renal
- prostate
- Boneris 3rd commonest for metastatic disease ( after lung, liver)
- usually >40 yrs
- common sites
- axial skeleton- thoracic spine most common site
- proximal limb girdle
- prox femur most common site of fx 2ary to met bone lesion
2
Q
What is the pathophysiology of bony mets?
A
- Mechanism of osteolysis
-
osteolytic bone lesions - caused by Tumour induced activation of osteoclasts
- occurs thru RANK, RANKL, osteoprotegrin
- Osteoblastic bone mets are due to tumour secreted endothelin 1
-
osteolytic bone lesions - caused by Tumour induced activation of osteoclasts
3
Q
What is the prognosis of pts with metastatic disease with thyroid, prostate, breast, kidney and lung?
A
- Thyroid 48 months
- Prostate 40 months
- Breast 24 months
- Kidney variable short as 6 months
- Lung : 6 months
4
Q
Name associated conditions of metastatic disease?
A
-
Metastatic hypercalaemia
-
medical emergency
- confusion
- muscle weakness
- polyuria/polydipsia
- nausea/vomiting
- dehydration
- tx with hydration and loop diuretics
-
medical emergency
5
Q
describe the mechanism of metastasis?
A
- Tumour cell intravasation
- E cadherin cell adhesion molecule on tumour cells modulates release from primary tumour focus into bloodstream
- Avoidance of immune surveillance
- target tissue localization
- induction of angiogenesis - via vascular endothelial growth factor (VEGF) expression
- genomic instability
- decreased apoptosis
-
Vascular spread
- Batson’s vertebral plexus
- valveless venous plexus of the spine that provides a route of metastasis from organs to axial structure including vertebral bodies, pelvis, skull and prox limb girdles
-
Arterial tree metastasis
- mechanism which lung/renal cancer spreads to distal extremities
6
Q
What are the symptoms of metastatic disease?
A
- Pain
- mechanical due to bone destruction or tumorigenic pain at night
- Pathological Fx 8-30%
- metastatic hypercalcaemia
- O/E
- Neurological deficit
- compression of spinal cord with mets disease to spine
- Neurological deficit
7
Q
Describe the workup for a pt with suspected metastatic diseasee?
A
-
Plain radiographs
- lung, thyroid & renal = lytic
- 60% breast ca= blastic
- 90% prostatic ca= blastic
- lesions distal to elbow/knee often lung/renal primary- see pic
- CT chest /adbo/Pelvis
-
Technetium bone scan- to detect extent of disease
- myeloma & thyroid ca are cold
- elevate with skeletal survey if cold
- Labs
- U&E
- ESR
- LFT’s, CA, Phos, Alk Phosphatase
- serum & urine immunoelectrophoresis
-
Biopsy
- shouldn’t tx bone lesion without tissue dx
8
Q
What is the goal of tx in metastatic disease?
A
- Control pain
- Maintainence of patient independence
9
Q
What is the tx of metastatic disease?
A
Non operative
- Bisphosphonates
- symptomatic to prevent osteclastic bone destruction
- iv pamidronate most commonly used
Operative
-
Stabilisation of complete fx, postop radiation
- most complete fx are treated if op stabilisatio leads to improved quality of life
-
post op radiation
- all pts unless death immunent or area has had previous radiation
- begin radiation after surgery
- area of irradiation should include entire fixation device
- Prophylatic stabilisation of impeding fx ( entire bone - ie nail) allow immediate WB, post op rdx
-
preop embolization
- renal cell carcinoma/thyroid as v vascular
10
Q
What is the tx for metastatic spinal lesion?
A
Non operative
-
Palliative care
- if life expectancy< 6months
Operative
-
Neurological decompression, spinal stabilisation adn post op radiotherapy
- for met lesions to spine with neurological deficits in pts with life expectancy > 6 months
- preop embolisation included for renal ca to psine
11
Q
Are there any scoring systems to help decide prognosis of spinal mets and so tx?
A
- Tokuhashi et al Spine 2009. published a scoring system to help develop a treatment algorithm for patients with metastatic spinal lesions.
- They used a patient’s
- general condition
- number of extraspinal bone metastases
- the number of metastases in the vertebral body,
- the metastases to other major internal organs,
- the primary site of the tumor,
- degree of neurologic compromise to determine the life expectancy.
- They recommended against surgical intervention for patients with less than six months to live.
12
Q
What is a Giant cell tumour?
A
- A Benign Agressive Tumour
- typically found in Epiphysis of long bones but may airse in apophysis ( like chondroblastomas)
- > females (cf most bone tumours)
- Age 30-50 yrs
- location
- 50% around knee
- **10% sacrum/vertebra body**
- distal radius
- phalanges also common
- may a
13
Q
Describe the malignancy of gct?
A
-
Primary malignant giant cell tumour
- mets to lung in 2-5%
- hand lesions have > chance of metastasis
-
Secondary malignant giant cell tumour
- occurs following radiation/multiple resections of GCT
14
Q
What are the symptoms of GCT?
A
- Pain refered to involved joint
O/E
- palpable mass
- decreased rom of joint
15
Q
What is seen on imaging a GCT?
A
Xrays
- An Eccentric Lytic Epiphyseal/Metaphsyeal lesion
- often extends into the distal epiphysis and borders subchondral bone
Bone scan
- Very hot
MRI
- Demarcation on T1 image between fatty marrow and tumour- see pic
16
Q
Describe the histology of GCT?
A
- Neoplastic cell is the mononuclear stromal cell- see pic
- Hallmark giant cells are numerous
- secondary aneurysmal bone cysts not unusual
18
Q
What is Ewing’s sarcoma?
A
- A distinctive round cell bone sarcoma
- 5-25 yrs
- 2nd most common bone tumour in children
- Uncommon in african americans/chinese
- 50% Diaphysis of long bones
- locations
- Pelvis, distal femur, proximal tibia, femoral diaphysis, proximal humerus
- Genetics
- t( 11:22) translocation - in all cases
- which leads to -> Fusion protein ESW-FLI1= identified w PCR
20
Q
What is the symptoms of Ewing’s sarcoma?
A
- Pain accompanied by fever
- often mimics infection
O/E
- Swelling and local tenderness
21
Q
What are the signs of Ewing’s sarcoma on imaging?
A
Xray
- Large destructive lesion in Diaphysis/metaphysis with a Moth eaten appearance- see pic
- Lesion maybe purely lytic or somereactive bone formation
- Periosteal reaction= onion skin/sunburst appearance
Bone Scan
- Hot lesion
MRI
- often shows large soft tissue component
CT chest
- Bony Mets
23
Q
What is seen on histology with Ewing’s sarcoma?
A
- Gross- may have liquid consitency like pus
- sheets of monotomous small round blue cells- see pic
- prominent nuclei and minimal cytoplasm
- may have pseudo-rosettes ( circle cells w necrosis in centre)
- Immunostaining
- CD99 reactivity
26
Q
What is an Adamantioma?
A
- A rare low grade Malignant tumour of unknown aetiology that is almost always located in the mid-tibia
- <300 cases documented
- young adults 20-40 yrs
27
Q
Name associated conditions of adamantinoma?
A
-
Osteofibrous dysplasia
- not a precusor of adamantinoma
- a BENIGN, fibro-osseous lesion in the tibia cortex of young children
- Tx by observation
29
Q
What are the symptoms of adamantinoma?
A
- Pain of months- years duration
O/E
- Bowing deformity of tibia
- Palpable mass of tibia
30
Q
What is seen on imaging of adamantinoma?
A
- xray
- Multiple sharply circumscribed lucent lesions “soapy bubbles” with interspersed sclerotic bone in mid tibia
- some lesions mat destroy cortex
- may see bowing of tibia
- radiographic evolution of lesion helpful as lesions may continue to grow and erode cortex
- No periosteal reaction
