CORTEX pathology Flashcards
List the possible causes of a benign bone tumour
Neoplastic Developmental Traumatic Infectious Inflammatory
Which is more common primary bone cancer or metastatic disease?
Metastatic disease by far
What is the most common benign bone tumour? Describe this tumour
Osteochondroma
Bone outgrowth with cartilaginous cap
How do osteochrondromas present?
Asymptomatic
Local pain
Osteochondromas, while benign, carry a high malignant transformation risk. T/F
False - risk of malignant transformation low
When might multiple osteochondromas occur?
Autosomal dominant hereditary disorder
Describe an enchondroma. Why do they occur?
Intramedullary, metaphyseal cartilaginous tumour
Failure of normal endochondral ossification
How do enchondromas appear radiologically?
Lucent radiologically +/- sclerotic areas
How do enchondromas present?
Asymptomatic
Pathological fractures
Which bones do enchondromas occur within?
Femur
Humerus
Tibia
Hand & feet (phalynx)
How can enchondromas be treated?
Curattege of lesion
Filling with bone graft
What are simple bone cysts sometimes called?
Unicameral bone cysts
Describe a simple bone cyst. What causes them?
Single cavity fluid filled cyst in bone (metaphysis in long bones)
Defect in the physis
Which bones do simple bone cysts occur within?
Long bones (femur, humerus)
Talus
Calcanus
How do simple bone cysts present?
Asymptomatic
Pathological fracture
How can simple bone cysts be treated?
Curattege of lesion
Filling with bone graft
+/- stabilisation
Which age group is usually diagnosed with simple bone cysts? How are they diagnosed?
Young adults/children
Incidentally on x-ray
Describe an aneurysmal bone cyst
Multichambered cyst filled with blood or serum occuring in metaphyses
What causes aneurysmal bone cysts?
Arteriovenous malformation
Which bones do aneurysmal bone cysts usually occur within?
Long bones
Flat bones (skull, ribs)
Vertebral bodies
How do aneurysmal bone cysts present?
Locally aggressive –> pain
Pathological fracture
How are aneurysmal bone cysts treated?
Curettege
Filling with bone graft
Describe a giant cell tumour of the bone
Radiolucent lesion affecting metaphyseal, epiphyseal or even subchondral bone near joints
Which bones do giant cell tumours usually occur within?
Knee
Distal radius
Long bones
Pelvis
Spine
How do giant cell tumours characteristically appear on x-ray?
Soap bubble appearance
How do giant cell tumours present?
Locally destructive –> pain
Pathological fracture
Metastases to lung (benign GCT)
How are giant cell tumours treated?
Intralesional excision + phenol/bone cement/liquid nitrogen to destroy residual tumour (& prevent reoccurrence)
Joint replacement in aggressive lesions
In which age group does fibrous dysplasia occur?
Adolescents
Why does fibrous dysplasia occur?
Genetic mutation causing lesions of fibrous tissue & immature bone
Does fibrous dysplasia affect one bone or many?
Either - monostotic or polystotic
How do bones affected by fibrous dysplasia appear?
Angular deformities
Wide bone with thin cortices
How does fibrous dysplasia present?
Pain
Stress fractures
What type of deformity can occur in fibrous dysplasia and what bone does this involved?
Proximal femur - shepherd’s crook
Describe the typical bone scan result in fibrous dysplasia
Increased uptake during development followed by inactivity
How can fibrous dysplasia be managed?
Biphosphonates (pain reduction)
Fixation of stress fractures
Cortical bone grafts (improves strength)
Why is intralesional excision NOT used in fibrous dysplasia?
Reoccurrence rate high
How does an osteoid osteoma present?
Small nidus of immature bone surrounded by sclerotic halo
Which age group gets osteoid osteomas?
Adolescents
Which bones do osteoid osteomas commonly occur within?
Proximal femur
Diaphysis of long bones
Vertebrae
How do osteoid osteomas present?
Intense constant pain Night pain (inflammatory response) Pain relieved by NSAIDs
How are osteoid osteomas investigated?
X-ray (not diagnostic)
Bone scan
CT
How are osteoid osteomas managed?
Self resolving
CT guided radiofrequency ablation
En bloc excision
What is a brodie’s abscess?
Subacute osteomyelitis which shows up as lytic bone lesion
What is a brown tumour?
Lytic bone lesion associated with hyperparathyroidism
How do bony metastases present?
Intense constant pain Worse at night Systemic symptoms (weight loss, anaemia, loss of apetite)
In which age groups would unexplained bone pain be most concerning?
> 60
Are bony swellings a cause for concern?
When paired with red flags or constant bony pain
How do cancer affecting the bone appear on x-ray?
Cortical destruction Periosteal retraction (raised & producing new bone) Sclerosis Lysis Extension into soft tissues
What is the most common form of primary bone cancer?
Osteosarcoma
Who gets osteosarcoma?
Young adults
Which bones does osteosarcoma most commonly affect
Knee
Proximal humerus
Proximal femus
Pelvis
How does osteosarcoma typically spread?
Haematogenous (can spread lymphatically but less common)
Where does osteosarcoma commonly metastasis to?
Lungs
Osteosarcomas are sensitive to which treatment?
Excision
Chemotherapy (as adjuvant - not curative)
NOT radiotherapy
What is chondrosarcoma?
Cartilage producing primary bone tumour
Which age group commonly gets chondrosarcoma?
Adults (median age 45)
Chondrosarcomas are typically small and fast spreading. T/F
False - large and slow spreading
Where are chondrosarcomas most commonly found?
Pelvis
Proximal femur
How are chondrosarcomas treated?
NOT radio OR chemotherapy
Excision
Which two fibrous primary bone tumours tend to occur in pathological bone? List conditions associated with pathological bones
Fibrosarcoma
Malignant fibrous histiocytoma
Paget’s
Fibrous dysplasia
Post irradiation
Bone infarct
Which age group is affected by fibrosarcoma?
Adolescents and young adults
What is Ewing’s sarcoma? How common is it? What is it’s prognosis?
Malignant tumour of primitive cells in bone marrow
Second most common
Really shitty
Which age group tends to get Ewing’s sarcoma?
10-20 y/o
How does ewing’s sarcoma present? What is it commonly misdiagnosed as?
Bone pain
Fever
Raised inflammatory markers
Warm swelling
Osteomyelitis
How is ewing’s sarcoma treated?
Excision
Radio and chemotherapy
How are primary bone tumours staged?
Bone scan
CT chest
MRI/CT (local spread)
Biopsy
What is lymphoma?
Cancer of round cells/macrophages
How does lymphoma affect the bone? Which bones does it tend to affect?
Primary bone tumour (non-hodkins)
Metastatic
Pelvis
Femur
How is lymphoma of the bone treated?
Excision
Chemo/radiotherapy for metastatic
What is myeloma?
Malignant B cell proliferation & antibody production
What are the two forms of myeloma? How do they differ?
Plasmacytoma - solitary lesion
Multiple myeloma - multiple osteolytic lesions
Which age group is typically affected by myeloma?
45-65
How does multiple myeloma present?
Weakness Back pain Bone pain Fatigue Weight loss Marrow suppression (anaemia & recurrent infection) Pathological fracture
How is multiple myeloma diagnosed?
Plasma protein electrophoresis (high paraprotein)
Early morning urine collection (Bence Jones proteins - overflow proteinuria)
Metastases are not always detected on bone scan of multiple myeloma. Why? How is this overcome?
Normal osteoblastic response to bone lysis is not present
Skeletal survey
How is myeloma treated?
Plasmacytoma - radiotherapy
Multiple myeloma - chemotherapy
Which cancers commonly metastases to bone? State whether they are lytic or sclerotis
Breast - either Prostate - sclerotic Lung - lytic Renal cell - lytic Thyroid adenocarcinoma
How are renal cell bony mets different from other mets?
Large and vascular - can bleed profusely on biopsy/surgery
Which bones are frequently metastasised?
Vertebrae Pelvis Ribs Skull Humerus Long bones of lower limb
Bone pain with any red flag symptom should be investigated how?
X-ray
How should bony lesions be investigated?
Bone scan (occasionally MRI) Blood tests (serum calcium - raised ; LFTs - mets ; plasma protein electrophoresis - myeloma ; FBC ; U&E)
Skeletal stabilisation and/or joint replacement is often indicated for pre-emptive treatment of pathological fractures. T/F
True - if high risk
When might soft tissue swellings be diffuse?
Synovitis (around joint)
Oedema
When might soft tissue swellings be local?
Bursitis Rheumatoid nodules Abscess Cystic lesions (ganglion, meniscal, baker's) Benign or malignant neoplasm
What should be looked for on examination of soft tissue swellings?
Site(s) Size Border Consistency Surface Mobility Temperature (infection) Transilluminable Pulsatility Skin changes Lymphadenopathy
Which features suggest benign soft tissue swelling?
Small Fluctuation in size Cystic lesions Well defined Fluid filled Soft/fatty
Which features suggest malignant soft tissue swelling?
Large (>5cm) Rapid growth Solid Ill defined Irregular Lymphadenopathy Systemic symptoms
How may soft tissue swellings be investigated?
MRI
USS (if suspected cystic)
Biopsy
ONLY if cause unknown with unclear clinical picture
What is the commonest benign soft tissue swelling? What is this?
Lipoma
Neoplasm of fat tissue
Where do lipomas occur?
Subcutaneous fat
Rarely within muscle
What is a giant cell tumour of the tendon sheath? How does it present?
Exactly what it says on the tin
Swelling found on flexor tendon sheath of finger
Painful
+/- bone erosion
How are giant cell tumours of the tendon sheath treated?
Excision has high reoccurrence rate
Not malignant so leave them alone
What are giant cell tumours of the tendon sheath known as when they involve a synovial joint? How do they present?
Pigmented Villonodular Synovitis
Pain +/- effusion in knee
Malignant tumours arising from the connective tissues are called what?
Sarcomas
Which age group most commonly gets sarcomas?
50-70 but can occur at any age
What is a ganglion cyst? Where are they most commonly found?
Herniation of weak portion of joint capsule/tendon sheath occuring around synovial joints
Wrist
What causes ganglions?
Congenital weakness (juvenile Baker's cyst) Underlying joint damage (arthritis --> adult Baker's cyst, mucous cyst of DIP, wrist ganglion)
Describe a ganglion
Well circumscribed
Transilluminate
Firm
Are ganglions excised?
It can be done but will reoccur so try to avoid this
What is buristis?
Inflammation of bursa
What is a bursa?
Small fluid filled sac lined with synovium preventing friction at a joint
What are the common areas for bursitis? Why does it occur?
Pre-patellar
Olecranon
Bunion (medial 1st metatarsal head)
Repeated pressure/trauma
Bacterial infection (abscess)
Gout
How are sebaceous cysts managed?
Excision +/- biopsy
What are the causes of abscesses on a limb? How are the managed?
Cellulitis
Bursitis
Penetrating wound
Infected sebaceous cyst
Must incise and drain pus
What is the end result of osteochondritis and AVN? Why does this occur?
Necrosis
Disrupted blood supply to the area –> ischaemia
Who gets osteochondritis? Why?
Young adults & children
Physical activity with repeated stress
Familial
Coagulopathy
How might repeated impaction or traction injuries cause osteochondritis?
Bleeding and oedema within bone –>
Capillary compression –>
Reduced blood supply –>
Necrosis
What is the result of necrosis in osteochondritis?
Compression/fragmentation/separation of bone +/- overlying cartilage –>
Irregular joint surface –>
Osteoarthritis at a young age
What are the common sites of compression osteochondritis?
Second metatarsal head (Freiburg's) Navicular bone (Kohler's) Lunate (Kienbock's) Capitellum (Panners) Vertebral (Scheuermann's disease)
What is traction osteochondritis and at which sites does it commonly occur?
Osteochondritis occuring at apophysis
Tibial tubercule (Osgood Schlatters) Calcaneus (Sever's disease)
Define osteochondritis dissecans. Where does it commonly occur?
Fragmentation with separation of bone and cartilage within a joint
Lateral part of medial femoral condyle of knee
Anteriomedial talar done
Superomedial femoral head
Humeral capitulum
How does osteochondritis dissecans present?
Pain
Locking
Effusions
Giving way of joints
How is traction osteochondritis treated?
Settles with test
How can osteochondritis and osteochondritis dissecans be treated respectively?
Osteotomy (joint damage)
Pinning of fragments +/- excision of detached parts
What is avascular necrosis (AVN) and in which age group does it occur?
Ischaemic necrosis of bone
Adults
Which sites are prone to AVN?
Femoral head Femoral condyles Head of humerus Capitulum Proximal pole of scaphoid Proximal part of talus
Which pathologies can AVN be secondary to?
Femoral neck fracture
Proximal humerus fracture
Waist of scaphoid fracture
Talar neck fracture
Is AVN ever idiopathic?
Yep
How can alcoholism, primary hyperlipidaemia and steroids cause AVN?
Mobilise fats into circulations where they get lodged in small vessels & increased fat content of bone can compress venous outflow
Which causes of increased coagulation are linked to AVN?
Thrombophilia
Sickle cell disease
Antiphospholipid deficiency in SLE
What is a rare cause of AVN?
Decompression sickness after deep sea diving (due to nitrogen bubbles)
How does AVN progress?
Necrosis --> Patchy sclerosis --> Subchondral collapse --> Irregularity of articular surface --> Secondary OA
How is AVN managed?
If not yet collapsed and in amenable site (e.g femoral head) drilling under fluroscopy can relieve pressure
Joint replacement or fusion if collapse
