Pathology Flashcards
How common are malignant primary bone tumours?
Very rare
How common is skeletal metastatic cancers?
Common
What is the most common benign bone tumour?
Osteochondroma
What is an enchondroma?
Metaphyseal cartilaginous tumour caused by failure of normal enchondral ossification at the growth plate
Where do simple bone cysts commonly occur?
Long bones.
What are the symptoms of simple bone cysts?
Usually asymptomatic but can cause bone weakness
What causes an aneurysmal bone cyst?
Arteriovenous malformations
Giant cell tumours are locally aggressive. Where do they commonly affect?
Around the knee and distal radius and other long bones.
What do giant cell tumours look like on x-ray?
Soap bubble appearance
What are the red flag symptoms of metastatic bone cancer?
Severe constant pain
Worse at night
What do malignant primary bone tumours show on x-ray?
Cortical destruction and a periosteal reaction
What is the most common primary malignant bone tumour?
Osteosarcoma
What age group is an osteosarcoma most likely to affect?
Adolescents and young adults
Where is an osteosarcoma most common?
Around the knee.
What is a chondrosarcoma?
A malignant hyaline cartilage producing primary bone tumour.
Mean age: 45
Where are chondrosarcomas found?
Pelvis
Proximal femur
What is Ewing’s sarcoma?
Malignant tumour of primative cells.
2nd most prevalent primary bone tumour.
Poorest prognosis.
Occurs in people 10-20 .
Which primary malignant tumour metastasises to bone most commonly?
Breast Ca
If breast Ca has spread to bone, how long is the prognosis?
24 months
What features are suggestive of a malignant soft tissue neoplasm?
> 5cm
Rapid growth
Solid, ill defined
Associated lymphadenopathy
What is the most common soft tissue tumour?
Lipoma
What is a ganglion cyst?
Occurs around a synovial joint.
Forms as a result of a herniation of the joint capsule.
What does a Ganglion cyst look like?
well defined, firm, transilluminate.
What can cause bursitis?
Repeated pressure or trauma
What is a possible consequence of osteochrondritis?
Localised necrosis due to ischaemia
What is avascular necrosis (AVN) ?
Ischaemic necrosis which commonly occurs in adults.
True or False
AVN is always idiopathic
False
Can be secondary to fractures or due to alcoholism or steroids
On xray what disease can present as bone enlargement, thickened corticles and trabeculae?
Paget’s disease where bone repairal is chaotic.
Where does Paget’s disease commonly affect?
Pelvis
Femur
Skull
Tibia
In what kind of tumour would a Shepherd’s crook deformity be found in the proximal femur?
Fiberous dysplasia
What is a fascicle?
Group of muscle fibres
What surrounds a fascicle?
Perimysium
What sounds the individual muscle fibres?
Endomysium
In skeletal muscle, where are the nuclei positioned?
At the cell periphery
Why is glycolysis high in white fibres?
Not much mitochondria
Not much myoglobin.
operates mainly on anaerobic-generated ATP.
What would a high creatinine kinase level indicate?
Dystrophy
What would dystrophic changes look like on staining?
Variable muscle fibre sizes Fatty infiltration Myocyte hypertrophy Central nuclei Ring fibres
Which 2 muscular dystrophies are X linked?
Duchenne (DMD)
Becker (BMD)
Which are essentially the same thing but BMD affects later in life
When does DMD usually present?
Preschool.
2-4.
Will not live past 20
What gene is responsible for DMD?
Mutations on dystrophin gene on chromosome X
What does the mutation in DMD mean happens intracellularly?
Actin cytoskeleton is altered so it does not anchor to the basement membrane so muscle contractions do not occur properly.
What is seen on histology of DMD?
Muscle fibre necrosis
Chronic inflammation
What is myotonic dystrophy?
DM1 and DM2
Autosomal dominant.
Muscle weakness and myotonia
What are the symptoms of myotonic dystrophy?
weakness in face and distal limbs
Cardiomyopathy
Low intelligence
Cataracts
What is seen on histology of myotonic dystrophy?
Atrophy of type 1 red fibres
Central nuclei
Fibrofatty replacement
What are the primary inflammatories of muscle?
Infective agents e.g. coxsackie
Polymyositis
Dermatomyositis
What is polymyositis?
Chronic inflammatory disease of unknown cause
What T cells are involved in polymyositis?
CD8+
What is dermatomyositis?
Polymyositis plus skin changes e.g. erythema
True or False
There is a 70% risk of malignancy with dermatomyositis
False.
10% risk of malignancy
What T cells are involved in dermatomyositis?
CD4 cells.
What do the muscle fibres look like in neurogenic muscular disorders in adults?
Small, angulated muscle fibres.
Fibre grouping occurs in neurogenic muscular disorders. What does this mean?
Type I fibres all clump together instead of being spread out.
Where does the fault lie in motor neuron disease?
The anterior horn of spinal cord cells.
What is fasciculation?
Uncontrolled muscle twitching
What is spinal muscular atrophy?
Degeneration of anterior horn of spinal cord cells but INHERITED, unlike MND.
What is myasthenia gravis?
Autoantibodies to the ACh receptor in the post synaptic cleft.
Who does Myasthenia gravis affect most commonly?
Women aged 20-40
What is rhabdomyolysis?
Breakdown of skeletal muscle
What are the antibodies involved in SLE?
Antinuclear antibodies (ANA)
In what way can SLE be classified as a type II and type III hypersensitivity?
type III due to IgG and C3 immune complexes in kidney
type II due to direct haemolysis leading to anaemia
What is polyarteritis nodosa?
Inflammation and necrosis of small/medium arteries, especially kidneys, heart, liver.
What autoantibody is found in serum for PAN?
pANCA
What is scleroderma?
Excessive collagen production, leading to excessive fibrosis of organs and tissues
Describe an osteochondroma
Cartilage capped bony projection on the external surface of a bone
Who is an osteochondroma more common in?
Young people
Where do osteochondromas tend to develop?
Epiphyses of long bones
What is a chondroma?
Benign hyaline cartilage tumour which rises in the medulla of the bone in hands and feet
What is the syndrome called when there are many chondromas?
Mafucci’s syndrome
Which age group does chondromas affect?
Young adults
What is Ollier’s disease?
Single chondroma which has a 10% malignancy transformation.
What is an osteoid osteoma?
Benign tumour of a central core of vascular osteoid tissue
Are osteoid osteoma tumours painful?
Yes and worse at night. May be accompanied by swelling and tenderness
Where are osteoid osteomas found?
Axial skeleton
What is the treatment for osteoid tumours?
They are self resolvable and can be managed with NSAIDs
What is a chondroblastoma?
Benign cartilage tumour in bone
Where are chondroblastomas found?
Epiphysis of long bones
What do chondroblastomas look like on histology?
Closely packed polygonal cells. “Chicken wire” calcification.
What is the treatment for chondroblastomas?
Biopsy and curettage plus liquid nitrogen
Who do giant cell tumours most commonly affect?
25-40 yrs old women
Why are giant cell tumours locally aggressive?
They destroy the medulla and cortex and may expand into soft tissue
What do giant cell tumours look like on histology?
Multinucleated giant cells in a seal of round mononuclear cells.
What is an osteoblastoma?
Benign and self-limited tumour that produces osteoid and bone.
What do osteoblastomas look like, grossly?
Red in colour with haemorrhagic areas.
What do osteoblastomas look like on histology?
Irregular, mineralised bone. Woven bone.
What is the treatment for an osteoblastoma?
Intralesional excision
What is a chordoma?
Benign but locally destructive.
Very rare
Who is a chordoma more common in?
Older females
Where are chordomas most common?
In the midline- often sacral region
Why is an osteosarcoma painful?
the periosteum is being eroded
Who does Ewing’s sarcoma most commonly affect?
20 year old males
What is a multiple myeloma?
Malignant proliferation of plasma cells in marrow.
