1- Pathology Flashcards
What are the symptoms of osteochondroma
Usually don’t cause any problems
May produce localised pain
Can osteochondromas malignantly transform
Very small risk
Signs include lesion that grows in size or produces significant pain
Benign bone tumours are more common than primary malignant ones - true or false
True
What are some potential causes of benign bone tumours
Neoplasm Developmental Trauma Infection Inflammation
Enchondromas are usually asymptomatic - true or false
True
Often an incidental finding
What is a common complication of enchondroma
Weakening of the bone leading to pathological fracture
Which bones do simple bone cysts usually occur in
Long bones - proximal humerus and femur
Talus or calcaneus
What are the symptoms of a simple bone cyst
Usually asymptomatic
Can weaken the bone and cause pathological fracture
How do you treat enchondroma
If risk of fracture or one has already occurred you can scrape it out and fill with a bone graft to strengthen
How can you treat a simple bone cyst
If risk of fracture or one has already occurred you can scrape it out and fill with a bone graft to strengthen
What is thought to be the cause of aneurysmal bone cysts
Small arteriovenous malformations
Where do aneurysmal bone cysts occur
The metaphyses of many different long bones, flat bones (ribs, skull) and vertebral bodies
Describe the presentation of an aneurysmal bone cyst
Usually painful
Locally aggressive and causes cortical expansion and destruction
May cause pathological fracture
How do you treat an aneurysmal bone cyst
Curettage (scraping out) and grafting
Or use bone cement
Which region of a bone does a giant cell tumour tend to affect
Predilection for the metaphyseal region
Also tend to involve the epiphysis and can extend to the subchondral bone adjacent to the joint.
How does a giant cell tumour appear histologically
Consists of multi-nucleate giant cells
Can giant cell tumours metastasise
5% will metastasise to lung and cause benign pulmonary GCT
How do you treat giant cell tumours
Intralesional excision with use of phenol, bone cement or liquid nitrogen to destroy remaining tumour material & reduce the risk of recurrence.
Very aggressive lesions with cortical destruction may need joint replacement.
What is the cause of fibrous dysplasia
A genetic mutation which results in lesions of fibrous tissue and immature bone
What are the results of fibrous dysplasia
Defective mineralisation can lead to angular deformities, with the bone being wider with thinned cortices
Stress fractures can occur
Shepard’s crook deformity in the proximal femur
How do you treat fibrous dysplasia
Bisphosphonates may reduce pain
Pathological fractures should be stabilised with internal fixation
Bone grafts can improve strength
Which age group commonly gets osteoid osteomas
Adolescents
Which bones do osteoid osteomas usually affect
Proximal femur
The diaphysis of long bones
The vertebrae
How do you treat osteoid osteomas
NSAIDs for pain
May resolve spontaneously
May need CT guided radiofrequency ablation
Name 2 other conditions that can present with a lytic lesion of bone
Brodie’s abscess - subacute osteomyelitis
Hyperparathyroidism - Brown tumours
What are some red flag symptoms of malignant bone cancer
Constant pain - severe and often worse at night
Weight loss
Loss of appetite
Fatigue
Which groups should you be aware of malignant bone tumours
Over 60s - more likely to develop cancer so must investigate unexplained skeletal pain
Under 25s - unusual to have unexplained skeletal; pain so must investigate
What are some common signs of malignant primary bone tumours on x ray
Cortical destruction
Periosteal reaction - raised periosteum producing bone
New bone formation
Extension into the surrounding soft tissue envelope.
Which bones are more commonly affected by osteosarcoma
Knee - 60% of cases
Proximal femur
Proximal humerus
Pelvis
How does osteosarcoma spread
Usually haematogenous spread but can be lymphatic
10% of patients will have lung mets on diagnosis
How do you treat osteosarcoma
Adjuvant chemotherapy can prolong survival
Not radiosensitive
Chondrosarcoma’s are small and slow to metastasize - true or false
False
Often very large but are slow to metastasise
Which bones are commonly affected by chondrosarcoma
Pelvis
Proximal femur
Can you treat chondrosarcomas with radiation or chemo
Nope
not radiosensitive and unresponsive to current chemo
What does a chondrosarcoma produce
Cartilage
Describe fibrosarcoma and malignant fibrous histiocytoma
Fibrous malignant primary bone tumours
Tend to occur in abnormal bone - e.g. bone infarct, Paget’s
Often affects adolescents or young adults
Which symptoms might Ewing’s sarcoma be associated with
Fever
Raised inflammatory markers
A warm swelling
Is Ewing’s sarcoma sensitive to common cancer treatments?
Yes
It tends to be radio‐ and chemo‐sensitive
Why might amputations be used in treatment of bone tumours
Usually to prevent recurrence
Limb salvage attempted with adjuvant therapy first
How do you stage a primary bone tumour
Bone scan - usually CT or MRI
CT of chest - look for mets
Why is biopsy required
For histological diagnosis
Grading prior to surgery
Lymphoma can occur as a primary bone tumour - true or false
True
Can originate from the marrow - Non Hodgkin’s
Lymphoma of any type can metastasize to the bone
Where does primary lymphoma of bone tend to affect
Pelvis
Femur
How do you treat primary lymphoma of bone
Surgical resection
How do you treat metastatic lymphoma
Chemo
Radiotherapy
Where does myeloma arise from
The bone marrow
What is multiple myeloma
Multiple osteolytic lesions throughout the skeleton
Which age group is most affected by multiple myeloma
Age 45-65
What is the common presentation of multiple myeloma
Weakness Back pain Bone pain Fatigue Weight loss May have marrow suppression resulting in anaemia and recurrent infection May present with pathologic fracture
How do you treat multiple myeloma
Chemotherapy
How do you treat a single lesion caused by myeloma
Radiotherapy
How do you diagnose myeloma
Plasma protein electrophoresis
Bence Jones protein assay - early morning urine sample
Bone scans
Which bones are most frequently involved in metastases
Vertebra Pelvis Ribs Skull Humerus Long bones of the lower limb
Which investigations should you do if you suspect metastases in the bone
Breast exam PR exam - if appropriate CXR - if lung suspected Bloods - serum calcium, LFTs, plasma protein, FBC Bone scans
How do you treat pathological fractures
Fractures or impending fractures are treated with stabilization using long rods
If there is joint destruction then joint replacement may be better
How can you improve symptoms of spinal cord compression due to spinal mets
Radiotherapy
Surgical decompression
Which soft tissue swelling are diffuse
Synovitis
Oedema
Which soft tissue swelling are local
Inflammatory ones - bursitis, rheumatoid Infection - abscess Cystic lesions Benign neoplasms Malignant neoplasms
What is a lipoma
Neoplastic proliferation of fat
Usually occurs in the subcutaneous fat
Can occur in muscle
Describe a giant cell tumour of the tendon
Small firm swelling
Usually found on the flexor tendon sheath of a finger
May not be painful
Can erode bone if large enough
What name is given to a giant cell tumour in the joint
Pigmented Villonodular Synovitis
Can cause pain and effusions
What is the general name for tumours of connective tissues
Sarcomas
gain more specific names from the type of tissue they arise from
Are sarcomas common
No - account for less than 1% of malignant tumours
What is an angiosarcoma
A malignant tumour from blood vessels
Which tissues do fibrosarcoma and malignant fibrous histiocytoma
Fibrous tissue
What is a liposarcoma
malignant tumour arising from fat
What is a rhabdomyosarcoma
malignant tumour arising from skeletal muscle
What is a synovial sarcoma
malignant tumour originating in the synovial lining of joint and tendons
Which age do sarcomas usually present
Between the ages of 50 and 70
How do you treat sarcoma
Usually surgically with adjunctive chemotherapy and/or radiotherapy
Describe the appearance of a ganglion cyst
Well-defined
Quite firm
Readily translucent
What treatment would you give for a ganglion cyst
May require excision if there is local discomfort or comesis
What can cause a ganglion cyst
Herniation or out-pouching of a weak portion of joint capsule or tendon sheath
Can be developmental
Or as a result of underlying joint damage leading to build up of pressure
What types of ganglion cysts are caused by developmental issues
Juvenile Baker’s cyst
What types of ganglion cysts are caused by joint damage and pressure
Adult Baker’s cyst
Mucous cyst of the DIP joint
Wrist ganglion
What is a bursa
Small fluid filled sac lined by synovium around a joint
It prevents friction between tendons, bones, muscle and skin
What is bursitis
Inflammation of a bursa
Usually occurs after repeated trauma or pressure
What can cause a bursal abscess
Bacterial infection
What can cause an abscess on a limb
Cellulitis
Bursitis
Penetrating wound
Infected sebaceous cysts
How do you treat abscesses
Incision and drainage
Antibiotics will not get into it
What is the general end result of osteochondritis and AVN
Bone undergoes localised necrosis
Due to ischaemia from a reduction in blood supply
Which age group tends to be affected by osteochondritis
Children
Young adults
What are some potential ‘causes’ of osteochondritis
Increased physical activity with repetitive stress
Familial predisposition
Recurrent impact or traction injury - causes bleeding
What are the consequences of osteochondritis
Bone necrosis
Results in compression or separation of bone
Causes flattening of joints
Pain and progression to arthritis
What are some common sites affected by compression in osteochondritis
2nd metatarsal head Navicular bone Elbow Vertebrae Hip - Perthes
What is osteochondritis dissecans
Fragmentation with separation of bone and cartilage
Can lead to pain, effusions and locking
How can you treat osteochondritis dissecans
Pinning of the unstable fragments
Remove detached fragments
How do you treat osteochondritis
If joint is damaged then osteotomy - surgical realignment of the bone
Can shift load from damaged area to undamaged
What sites are prone to AVN
Femoral head Femoral condyles Head of the humerus Capitellum Proximal pole of the scaphoid Proximal part of the talus.
What can cause AVN
Fractures that disrupt the blood supply Many cases are idiopathic Alcoholism Steroid use Hyperlipidaemia Thrombophilia Sickle cell Anti-phospholipid
How do you treat AVN
Dependent on stage
If articular surface is intact - drill to decompress bone
If surface is collapsed - joint replacement
