Musculoskeletal Neoplasms and Metastatic Disease Flashcards
What is the metaphysis?
The area between the diaphysis (shaft) and the epiphysis where the bone widens
What is the inside of bone and outside layer of bone called?
Compact bone = cortical bone = Outer layer of bone
Spongy bone = Trabecular bone = Cancellous bone = Inside layer of bone
Spongy bone + bone marrow = medullary cavity
What is lamellar bone and what is woven bone?
Lamellar bone = mature bone
Woven bone = osteoid = immature/new bone (can be produced by tumours)
What are the most common bone tumours?
Metastatic tumours from other parts of the body
What are the classes of bone tumours (classification by aetiology)?
Metastatic disease
Haematolymphoid malignancies (Plasma cell myeloma and Primary bone lymphoma)
Primary bone tumours (rare in comparison to metastases and haematolymphoid malignancies)
Which cancers most commonly metastasize to bone? (in order of incidence)
Lung, breast, prostate, colorectal adenocarcinoma
Thyroid adenocarcinoma
Renal Cell Carcinoma
Malignant melanoma
What are the types of bone metastases?
Osteolytic metastases: Bone is destroyed by tumour cells these are called osteolytic metastases. Cytokines stimulate osteoclastic bone resorption.
Osteoblastic metastases: Cytokines stimulate osteoblastic activity and new bone
Which cancers typically result in osteoblastic metastases?
Prostate and breast carcinomas
What are the most common types of haematolymphoid malignancies?
Plasma cell (multiple) myeloma
Primary bone lymphoma (haematology)
What is plasma cell myeloma?
Previously called multiple myeloma, bone marrow-based malignant neoplasm of plasma cells. Forms multiple tumours throughout skeletal system
What is the incidence of plasma cell myeloma?
Most common primary malignancy of bone. (usually in >50yo
What are the clinical symptoms of plasma cell myeloma?
Bone pain, pathological fracture (tumours in bone)
Hypercalcaemia (osteoclastic bone destruction)
Monoclonal immunoglobulin in serum and urine (clonal proliferation of plasma cells)
Renal failure (paraprotein deposits in kidney)
Susceptibility to infection (abnormal immunoglobulin)
Anaemia (Chronic disease)
What is an M protein/paraprotein?
Protein produced by abnormal plasma cells that have proliferated.
How are bone tumours identified?
Their clinicopathological features are relatively constant:
Age of patient
Bone and area affected
Radiological and pathological features (multidisciplinary bone tumour meeting)
How are bone tumours managed?
Several disciplines are involved because it can affect relatively young people.
What are the types of tumours and how are they further divided?
Bone forming (eg osteosarcoma)
Cartilaginous
Fibro-osseus
Fibrous/fibrohistiocytic
Giant cell rich
Cystic lesions
Miscellanious
These tumours are further divided into benign and malignant categories
What type of tumour is the osteosarcoma?
Bone forming malignant mesenchymal neoplasm (sacoma) producing bone matrix.
How common is osteosarcoma?
Most common primary malignant tumour of bone and most commonly affects children.
Males are slightly more commonly affected and there is a bimodal age distribution (10 - 20s and then >20 years old)
What are the risk factors for primary bone cancer?
Adolescents
Majority idiopathic
Hereditary retinoblastoma
Li-Fraumeni syndrome (p53 mutation)
Ionising radiation
What are the risk factors for secondary bone cancer?
Older adults
Underlying benign bone disease: Paget’s disease, benign bone tumours, chronic osteomyelitis
What are the clinical symptoms of osteosarcoma?
Nocturnal local bone pain
Palpable mass
Pathological fracture
Constitutional symptoms (fever, anorexia, weight loss, metastatic disease)
Destructive mass in medullary cavity invading through cortex that can be identified using Codman’s triangle on x-ray or sunburst pattern.
What is the prognosis for osteosarcoma?
80% 5 year survival rate in localised disease
30% 5 year survival rate in metastatic disease
What do osteosarcomas look like on histology?
Malignant tumour cells produce osteoid matrix in a delicate pericellular lacelike pattern. This is most prominent in osteoblastic variant.
What is an osteoid osteoma?
A benign bone-forming tumour.
How do osteoid osteoma present clinically?
Presents as nocturnal pain that is responsive to NSAIDs
Where are osteoid osteomas most commonly seen?
Affects people from 5 - 20 years of age and males twice as often as females.
It is seen on the long bones most often within the cortex.
How common is the osteoid osteoma?
It makes up 15% of all primary benign bone tumours
What does osteoid osteoma look like on histology and macroscopically?
It is a small circumscribed cortical-based lesion
Trabeculae of woven bone
Plump osteoblastic rimming
What is an enchondroma?
Benign intramedullary cartilaginous neoplasm
Where are enchondromas commonly seen?
In small tubular bones of hands and feet (phalanges) > long bones
How common are enchondromas?
25% of primary benign bone tumours
Who is most commonly affected by enchondromas?
Males and females equally in their 20s and 30s
What are the risk factors for enchondroma?
Multiple lesions are formed in Ollier’s syndrome
What is the clinical presentation of enchondroma?
Asymptomatic; it is often an incidental radiological finding.
Can cause pain with pathological fracture in some cases.
What is the prognosis of enchondromas?
Benign and can be treated with local curettage.
What does enchondroma look like histologically and macroscopically?
Radiologically:
Circumscribed cartilaginous lesion
Expanding medullary cavity of tubular bones
Histologically:
Nodules of hyaline cartilage
Sharp interface with trabecular bone
What is an osteochondroma?
Benign pedunculated tumour of bone with cartilage cap overlying bony stalk
Commonly called exostosis
How common are osteochondromas? Who are they most commonly seen in?
Most common benign bone tumours (50%)
Seen more in males than females that are 10 - 20 years of age.
Which part of the bone do osteochondromas most commonly affect?
Metaphyseal surface of long bones
What are the risk factors for ostechondroma?
Most common one is multiple hereditary exostosis which is an autosomal dominant condition.
What is the clinical presentation of osteochondroma?
Usually asymptomatic and seen on radiology indidentally (unless impinging on a nerve or if there is fracture of stalk)
What is the prognosis of osteochondroma like?
Benign and can be treated with conservative management
Symptomatic cases cured with simple excision
What does an osteochondroma look like radiologically and histologically?
Radiologically:
Pedunculated (mushroom-like) lesion arsing from metaphysis that points away from joint space
Stalk is continuous with medullary cavity
Histologically:
Cartilage cap (neoplastic part of the tumour)
Merges with underlying bony stalk through endochondral ossification
What is fibrous dysplasia?
A benign fibro-osseus tumour of bone.
Who most commonly gets fibrous dysplasia?
7% of primary benign tumours
Early to mid adulthood and affects axial skeleton more often than long bones.
What are the risk factors for fibrous dysplasia?
Usually it is monoastotic but can also be polyastotic (McCune-Albright syndrome)
It is non-inherited
How does fibrous dysplasia present clinically?
Most are incidental radiological findings.
What does fibrous dysplasia look like radiologically and histologically?
Radiologically:
Well-defined ground glass opacity within medullary cavity
Varus deformity in femur (shepherd’s crook)
Histologically:
Fibro-osseus tumour
Curvilinear arrays of woven bone (resembles chinese writing)
Fibrous stroma with bland spindle cells.
What is Ewing sarcoma?
A highly malignant small, round, blue cell tumour.
It is a primitive ectodermal tumour (PNET)
How common is ewing sarcoma and who is it most common in?
It makes up 10% of primary malignant bone tumours, affects children from 10 - 15 years of age and affects males more than females.
Primarily affects the long bones and pelvis
How does ewing sarcoma typically present?
Painfully enlarging mass
It is usually detected only after it becomes metastatic
What is the prognosis of ewing sarcoma?
5 year survival rate is 75%
Long term cure only in 50%
How is ewing sarcoma diagnosed?
Prototypical small round blue cell tumour with rosettes on histology (due to cells being almost completely nuclei)
EWSR1-FLI1 t(11;22) translocation on FISH
Diffuse CD99 staining immunohistochemistry
What is a sarcoma?
A malignant soft tissue tumour. (very rare)
How do soft-tissue tumours present clinically?
Palpable mass for extremity tumours
Abdominal distension for abdominal/retroperitoneal tumours
Things that increase suspicion for sarcomas:
Tumour size >5cm or enlarging mass
Deep-seated (deep to fascia/intramuscular)
Painful
Multiple lesions
How are soft tissue tumours classified?
WHO classification:
> 140 different subtypes
Histological classification:
Line of differentiation
Mature mesenchymal tissue which the tumour most closely resembles
