Unknown origin tumours Flashcards
Metastatic bone disease Giant cell tumour ewing's tumour Adamantioma
Describe metastatic cancer of bone?
- 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
What is the pathophysiology of bony mets?
- 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
What is the prognosis of pts with metastatic disease with thyroid, prostate, breast, kidney and lung?
- Thyroid 48 months
- Prostate 40 months
- Breast 24 months
- Kidney variable short as 6 months
- Lung : 6 months

Name associated conditions of metastatic disease?
-
Metastatic hypercalaemia
-
medical emergency
- confusion
- muscle weakness
- polyuria/polydipsia
- nausea/vomiting
- dehydration
- tx with hydration and loop diuretics
-
medical emergency
describe the mechanism of metastasis?
- 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

What are the symptoms of metastatic disease?
- 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
Describe the workup for a pt with suspected metastatic diseasee?
-
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

What is the goal of tx in metastatic disease?
- Control pain
- Maintainence of patient independence
What is the tx of metastatic disease?
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
What is the tx for metastatic spinal lesion?
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
Are there any scoring systems to help decide prognosis of spinal mets and so tx?
- 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.

What is a Giant cell tumour?
- 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

Describe the malignancy of gct?
-
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
What are the symptoms of GCT?
- Pain refered to involved joint
O/E
- palpable mass
- decreased rom of joint
What is seen on imaging a GCT?
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

Describe the histology of GCT?
- Neoplastic cell is the mononuclear stromal cell- see pic
- Hallmark giant cells are numerous
- secondary aneurysmal bone cysts not unusual

What is the tx of GCT?
Non operative
-
Radiation alone
- only inoperable/multiple lesions
- 15%-> malignant transformation
- Medical Mx
-
Bisphosphonates
- OC inhibitors- may decrease size of defect in GCT
-
Denosumab
- Monoclonal antibody against RANKL
- trails= decrease size of defect in GCT
-
Bisphosphonates
Operative
-
Extensive Currettage and Reconstruction ( w adj tx)
- lesions amenable to currettage
- hand lesions controversial
- if no cortical defect- currettage + cement
- if cortical defect- intercalary resection w fibular free graft vs amputation
- need to preform extensive exterioration ( removal of large cortical window over lesion ) is required
- Outcome 10-30% recurrence vs 3% w adjuvant tx ( phenol, hydrogen peroxide)
What is Ewing’s sarcoma?
- 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

What is the prognosis of Ewing’s sarcoma?
- 60-70% long term survival w isolated extremity disease
- 40% long term survival w pelvic lesions
- 15% long term survival if presents w mets
Poor prognostic factors
- Spine & pelvic tumours
- tumour >100cm3
- <90% necrosis w chemo
- elevated lactic dehydrogenase levels
- p53 mutation in addition to T(11:22) translocation
What is the symptoms of Ewing’s sarcoma?
- Pain accompanied by fever
- often mimics infection
O/E
- Swelling and local tenderness

What are the signs of Ewing’s sarcoma on imaging?
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

What is seen on lab results with Ewing’s sarcoma?
- Elevated WCC
- Elevated ESR
- Anaemia Common
- Lactic Dehydrogenase
- Bone marrow biopsy- to rule out mets in marrow
What is seen on histology with Ewing’s sarcoma?
- 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

Describe the tx for ewing’s sarcoma?
- Operative
- Chemotherapy and Limb Salvage Resection
- standard most pts
- preop chemo 8-12 wks then surgery then chemo 6-12 mo post
- Curent trend away radiotx
- only with resectable tumours/mets
- Chemotherapy and Limb Salvage Resection
What are the age differentials of small- round cell tumours?
- <5 yrs= Neuroblastoma/ Leukaemia
- 5-10 yrs= Esosinophilic Granuloma
- 5-30 yrs= Ewing’s sarcoma
- >30 yrs= lymphoma
- >50 yrs= myeloma
What is an Adamantioma?
- 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

Name associated conditions of adamantinoma?
-
Osteofibrous dysplasia
- not a precusor of adamantinoma
- a BENIGN, fibro-osseous lesion in the tibia cortex of young children
- Tx by observation

What is the prognosis of adamantinoma?
- May metastatize to lungs 25%
- so longterm follow up is recommended
- reocurrance is uncommon with negative margin excision
What are the symptoms of adamantinoma?
- Pain of months- years duration
O/E
- Bowing deformity of tibia
- Palpable mass of tibia

What is seen on imaging of adamantinoma?
- 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

What is seen in histology of adamantiomas?
- Fibrous and epithelial tissue in gland like pattern
- nests of epithelial like cells arranged in palisaing or glandular pattern
- background of stroma
What is the tx of adamatiomas?
- Operative
-
Wide margin surgical resection
- most pts
- often requires intercallary resection w allograft /megaprosthesis reconstruction
- Chemo and Radiotx typically not used