Pathology Flashcards
What surrounds the entire skeletal muscle?
epimysium
What surrounds the bundles of skeletal muscle fibres?
perimysium
What surrounds the individual muscle fibres?
endomysium
What are the 3 main indications for muscle biopsy?
- evidence of muscle disease (eg weakness, muscle symptoms, elevated CK)
- presence of neuropathy
- presence of vascular disorder (vasculitis)
what is fasciculation?
uncontrolled twitching of muscle
When CK level is higher than normal, in the ‘low’ classification, what type of disorder does this indicate?
neurogenic disorder
when CK level is higher than normal, in the ‘intermediate’ classification, what type of disorder does this indicate?
inflammatory myopathy
when CK level is higher than normal, in the ‘high’ classification, what type of disorder does this mean?
muscular dystrophy
what are the 5 main groups of myopathies?
- muscular dystrophies
- inflammatory myopathies
- congenital myopathies
- secondary myopathies
- metabolic myopathies
Why are ring fibres sometimes formed during muscle dystrophy?
condensation of the cytoplasm
Why can there be enlarged nuclei and increased number of nuclei during muscle dystrophy?
due to attempted regeneration co-existing with the atrophy
What type of inheritance is Duchenne’s Muscular Dystrophy (DMD)?
x-linked
What muscles does Duchenne’s Muscular Dystrophy (DMD) mainly affect?
muscles of the pelvic girdle
What type of inheritance is Becker’s Muscular Dystrophy (BMD)?
x-linked
What muscles does Becker’s Muscular Dystrophy (BMD) mainly affect?
muscles of the pelvic girdle
When is the onset of Duchenne’s Muscular Dystrophy (DMD)?
2 - 4 years old
What is the life expectancy of someone with Duchenne’s Muscular Dystrophy (DMD)?
20
What happens to the calves of patients with Duchenne’s Muscular Dystrophy (DMD)?
pseudohypertrophy
What mutation causes Duchenne’s Muscular Dystrophy (DMD)?
Mutations in dystrophin gene on long arm of chromosome X
What causes the different severities of Duchenne’s Muscular Dystrophy (DMD)?
mutations resulting in frame shift- severe
mutations resulting in altered binding- moderate to severe
mutations in middle rod- mild (Beckers)
What does the mutation in the dystrophin gene in Duchenne’s Muscular Dystrophy cause? (in terms of basement membrane and actin and Ca++ entry)
changes anchorage of actin cytoskeleton to basement membrane
uncontrolled Ca++ entry into cells
What does the change in anchorage of actin cytoskeleton to basement membrane in Duchenne’s Muscular Dystrophy do to the muscle fibres?
makes them more liable to tear
What gene is mutated in Becker’s Muscular Dystrophy (BMD)?
dystrophin
variant of DMD
compare disease progress of Beckers to Duchennes?
Beckers progression is much slower
What is myotonia?
inability to relax voluntary muscles after vigorous effort
What are inflammatory myopathies?
primary inflammation of muscle
What is polymyositis?
a chronic inflammatory myopathy
autoimmune
compare inflammatory myopathies to muscular dystrophies in terms of pain?
no pain in dystrophies, pain is present in inflammatory myopahties
What autoimmune proteins are found in polymyositis?
antibodies to muscle antigens
what type of lymphocytes are mainly involved in polymyositis?
cytotoxic lympocytes
what is dermatomyositis?
polymyositis with skin changes
a chronic inflammatory myopathy
autoimmune
What type of skin changes are present in dermatomyositis?
upper body erythema
swelling of eyelids with purple discolouration
what is the aetiology of polymyositis?
unknown
what is the aetiology of dermatomyositis?
unknown
but 10% associated with underlying malignancy
what type of lymphocytes are mainly involved in dermatomyositis?
helper T cells
compare the histology of polymyositis and dermatomyositis?
no histological differences, need to use other tests eg fluorescent staining
What are neurogenic disorders of muscle?
stereotyped changes after nerve damage with subsequent re-innervation
(pathology in motor neuron not muscle)
What is motor neurone disease?
progressive degeneration of anterior horn cells causing denervation atrophy, fasciculation and weakness
What type of inheritance is spinal muscular atrophy?
autosomal recessive
compare motor neurone disease to spinal muscular atrophy?
same pathology but different aetiology
MND is sporadic
spinal muscular atrophy is inherited
What is myasthenia gravis?
an autoimmune disease causing weakness, proptosis, fatigue and dysphagia
What is proptosis?
bulging of the eye
who commonly gets myasthenia gravis?
women between 20 and 40
what are the main causes of myasthenia gravis?
thymoma or thymic hyperplasia
What antibodies are produces in myasthenia gravis?
antibodies to ACh recepto in post-synaptic cleft
What is rhabdomyolysis?
breakdown of skeletal muscle
what are the 4 major side effects of rhabdomyolysis?
- myoglobinuria (which causes acute renal failure)
- hyperkalaemia
- necrosis
- shock
what are the main causes of rhabdomyolysis?
massive trauma
pressure induced
mushroom poisoning
drug side effects
What is the main management of connective tissue disorders?
anti-inflammatory/immunosuppression therapy
what antibodies are produces in SLE?
antinuclear antibodies (ANAs), anti-ds DNA, anti- Ro, anti-RNP
what skin effects of SLE can be seen?
butterly rash
discoid lupus erythematosus
what are the effects of SLE on the joints?
arthralgia
what are the effects of SLE on the kidneys?
glomerulonephritis
what are the effects of SLE on the central nervous system?
psychiatric symptoms
focal neurological symptoms
what are the effects of SLE on the cardiovascular system?
pericarditis
myocarditis
necrotising vasculitis
what are the effects of SLE on the immune system?
lymphadenopathy
splenomegaly
what are the effects of SLE on the lungs?
pleuritis
pleural effusions
what are the effects of SLE on haematological system?
anaemia
leukopenia
thrombophilia
what hypersensitivity reaction is SLE?
type 3 (visceral lesions)- deposition of IgG type 2 (haematological effects)- lysis of RBCs
What is polyarteritis nodosa?
inflammation and fibrinoid necrosis of small/medium arteries
what is the aetiology of polyarteritis nodosa?
unknown
small association with Hep B carriage
where is the pain and stiffness most present in polymyalgia rheumatica?
shoulder and pelvid girdle
no muscle weakness
what is the treatment for polymyalgia rheumatica?
steroids
prednisolone 15mg for 18 months
who are the people most likely to get polymyalgia rheumatica?
elderly women
when is pain and stiffness usually at its worst in polymyalgia rheumatica?
morning
what is termporal arteritis?
giant cell arteritis of the temporal artery (vasculitis)
what is scleroderma?
excessive fibrosis of organs and tissues due to excessive collagen production
scleroderma is associated with CREST syndrome, what is this?
calcinosis raynauds oesophageal dysfunction sclerodactyly telangectasia
what is sclerodactyly?
thickening of skin on fingers and toes
what is telangectasia?
dilation of small capillaries so they appear like red or purple clusters on teh skin
what are the 4 main causes of death for patients with scleroderma?
- renal failure (secondary to malignant hypertension)
- severe respiratory compromise
- cor pulmonale
- cardiac failure/arrhymias (secondary to myocardial fibrosis)
What is the name of a cartilage capped bony projection arising on the external surface of the bone which contains a marrow cavity continuous with that of the underlying bone?
osteochondroma
exostosis
who tends to develop osteochondroma?
males and females under 20
where do osteochondromas tend to develop?
epiphyses of long bones
what is the presumed cell of origin of osteochondromas?
chondrocytes
are osteochondromas benign or malignant?
benign
why can osteochondromas be surgically removed even if they are benign?
can sometimes cause pain or irritation
or if it’s growing in size (may become malignant)
what is a chondroma?
benign hyaline cartilage tumour
where do chondromas arise?
medullary cavity of bones of hands and feet
usually at metaphysis
who tends to get chondromas?
young adults
men > women
What is Mafucci’s syndrome?
multiple enchondromas associated with multiple haemangiomas
premalignant
What is Ollier’s Disease?
a rare developmental disorder involving multiple enchodromas of one extremity (usually unilateral)
(premalignant)
what type of inheritance is Ollier’s disease
not hereditary or familial
compare maffucci’s syndome to ollier’s disease in terms of malignant transformation risk?
Maffucci’s syndrome has a greater malignant transformation risk than Ollier’s disease
What is the name of a benign osteoblastic tumour composed of a central core of vascular osteoid tissue (immature) and peripheral zone of sclerotic bone?
osteoid osteoma
who tends to get osteoid osteomas?
children and young adults
M > F
where are osteoid osteomas found?
poximal femur,
diaphysis of long bones,
vertebrae
what is the distinct clinical picture of a person with an osteoid osteoma?
dull pain which is worse at night
pain relieved by aspirin or NSAIDs
what is the name of a benign cartilage tumour arising in bone?
chondroblastoma
where are chondroblastomas found?
epiphysis of long bones
who tends to get chondroblastomas?
20 -30 year olds
what is the treatment for a chondroblastoma?
biopsy and curettage
plus adjuvant liquid nitrogen
who tends to get giant cell tumours?
25-40 year olds
F > M
where is the site of giant cell tumours?
metaphsis and epiphysis long bones, often around the knee and distal radius
can occur in pelvis and spine
can involve subchondral bone and joint
what is the presumed cell of origin of a giant cell tumour?
osteoclast
is a giant cell tumour benign or malignant?
benign
but locally aggressve
what is the treatment for a giant cell tumour?
intralesional excision
very aggressive lesions may need joint replacement
what happens to giant cell tumours when they are radiated?
undergo malignant transformation
what is the name of a benign, self-limited tumour that produces osteoid and bone?
osteoblastoma
are osteoblastomas benign or malignant?
benign
but locally aggressive
where are osteoblastomas found?
metaphysis or diaphysis of long bones
what is the treatment for an osteoblastoma?
surgical resection by:
curettage
intralesional excition
en bloc resection
what is the name of a very rare tumour arising from notochord remnants?
chordoma
where are chordomas usually found?
midline
often in sacral region or base of skull
who tends to get chordomas?
40+
F > M
are chordomas benign or malignant?
benign
but locally aggressive
what is the treatment for chordomas?
generally difficult to resect
radiation may be helpful
chemotherapy for late stage disease
what is the name of a malignant tumour of osteoblasts which form osteoid?
osteosarcoma
who tends to get osteosarcomas?
young adults
older patients with predisposing conditions (eg Pagets)
M > F
where are osteosarcomas usually found?
bones around the knee,ie particularly distal femur, proximal tibia
also proximal femur, proximal humerous and pelvis
what needs to be produced by an osteosarcoma for diagnosis?
osteoid producion is essential for diagnosis
what are the 3 histological variants of conventional osteosarcoma?
osteoblastic
chondroblastic
fibroblastic
what is the treatment of an osteosarcoma?
biopsy, CT, bone scan
pre-op chemo
surgical resection
post-op chemo
what tumour is composed of malignant chondrocytes?
chondrosarcoma
which is the most common primary malignant tumour of bone?
osteosarcoma
what is the treatment of a chondrosarcoma?
wide surgical excision
what are the 3 main types of malignant bone cancer?
osteosarcoma
chondrosarcoma
Ewing’s Sarcoma
who tends to get Ewing’s Sarcoma?
10 - 20 year olds
M > F
what is Ewing’s Sarcoma?
a primary malignant tumour of the primitive cells in the bone marrw
where does Ewing’s Sarcoma occur?
metpahysis and diaphysis of:
- femur
- tibia
- humerous
what is the treatment of Ewing’s Sarcoma?
surgery
radiation therapy
chemotherapy
post-op adjuvant chemo
what is the name of the tumour caused by malignant proliferation of plasma cells in bone marrow?
multiple myeloma
who tends to get multiple myeloma?
elderly
what is the usual result of multiple myeloma?
bone destruction of axial skeleton
what is more common: primary bone tumours or secondary bone tumours?
secondary mets
what is the most common benign bone tumour?
osteochondroma
what type of inheritance is the hereditary disorder which causes multiple osteochondromas?
autosomal dominant
what are enchondromas caused by?
failure of normal endochondral ossification at the growth plate
why can enchondromas lead to pathological fractures?
because even though they are usually asymptomatic, they weaken the bone
what is the treatment for an enchondroma which has caused a fracture or is threatening to cause a fracture?
curettage (once one has healed)
+ filled with bone graft to strengthen bone
what is a simple bone cyst?
a single cavity, fluid filled, benign cyst in a bone
where are simple bone cysts generally found?
metaphysis of long bones particularly proximal femur and humerous
can be found in talus or calcaneous
why can simple bone cysts lead to pathological fractures?
because they weaken the bone
what is the treatment for a simple bone cyst?
curettage
+ filled with bone graft to strengthen
what is the probable cause of a simple bone cyst?
developmental defect
what is an aneurysmal bone cyst?
multiple fluid-filled chambers within a bone which contain blood or serum
what is the probable cause of an aneurysmal bone cyst?
small arteriovenous malformation
where do aneurysmal bone cysts occur?
metaphyses of long bones, flat bones and vertebral bodies
why do aneurysmal bone cysts cause pain?
because they are locally aggressive so cause cortical expansion and destruction
what is the treatment of an aneurysmal bone cyst?
curettage
+ filled with bone graft to strengthen
why are giant cell tumours of the bone painful?
destruction of cortex
despite being classified as benign, what typically malignant feature do they have?
can metastasise
usually causing benign pulmonary giant cell tumours
what is the characteristic sign of a giant cell tumour of the bone on an x-ray?
soap bubble appearance
what is the name of the genetic condition which results in lesions of fibrous tissue within bone and immature bone?
fibrous dysplasia
when does fibrous dysplasia tend to occur?
adolescence
compare monostatic fibrous dysplasia to polystatic fibrous dysplasia?
monostatic fibrous dysplasia- affects only one bone
polystatic fibrous dysplasia- affects more than one bone
what deformity is typical of fibrous dysplasia if there is extensive involvement of the proximal femur?
shepherd’s crook deformity
what can be used to reduce pain in fibrous dysplasia?
biphosphates
what should be done to treat pathological fractures caused by fibrous dysplasia?
internal fixation (for stability) and cortical bone graphs (for strength)
how do you treat osteoid osteomas?
many resolve spontaneously
others require CT guided radio-frequency alation or en bloc resection
what are the red flag symptoms for bone cancer?
constant pain worse at night systemic symptoms (eg weight loss, loss of appetite, fatigue)
are osteosarcomas radiosensitive?
no
where are chondrosarcomas likely to be found?
pelvis
proximal femur
compare osteosarcoma and chondrosarcoma in terms of mets rate??
osteosarcoma metastasizes faster than chondrosarcoma
are osteosarcomas responsive to adjuvant chemotherapy?
yes
are chondrosarcomas radiosensitive?
no
are chondrosarcomas responsive to adjuvant chemotherapy?
no
what are fibrosarcomas and malignant fibrous histiocytma?
fibrous malignant primary bone tumours which tend to occur in abnormal bone (eg bone infarcts, fibrous dysplasia and pagets disease)
which malignant bone cancer has the poorest prognosis?
Ewing’s Sarcoma
are Ewing’s Sarcomas radiosensitive?
yes
are Ewing’s Sarcomas responsive to chemotherapy adjuvants?
yes
what is neo-adjuvant chemotherapy?
chemotherapy given before surgery
What are the 5 most common primary malignant tumours which commonly metastasize to bone?
- breast carcinoma
- prostate carcinoma
- lung carcinoma
- renal cell carcinoma
- thyroid adenocarcinoma
what is the most common benign soft tissue tumour?
lipoma
what is a lipoma?
a neoplastic proliferation of fat
where do lipomas occur?
usually in the subcutaneous tissue,
can occur in the muscle
what is an angiosarcoma?
malignant tumour that arises from blood vessels
what is a liposarcoma?
malignant tumour that arises from fat
what is a rhabdomyosarcoma?
a malignant tumour that arises from skeletal muscle
what is a synovial sarcoma?
a malignant tumout that arises from the synovial lining of joints or tendons
what is a ganglion cyst?
a synovial-fluid-filled swelling that occurs around a synovial joint or synovial tendon sheath
(outpouching of synovium lining)
why do ganglion cysts form?
as a result of herniation or out-pouching of a weak portion of joint capsule of tendon sheath
what is a juvenile Baker’s cyst?
a ganglion cyst caused by a developmental weakness
what is an adults Baker’s cyst?
a ganglion cyst caused by a build up of pressure within the joint capsule
what is a bursa?
a small fluid filled sac lined by synovium around a joint which prevents friction between tendons, bones, muscles and skin
what can cause bursitis?
repeated pressure/trauma
bacterial infection
gout
how do you treat an abscess?
incision and drainage
will not resolve with antibiotics alone
what similar end result to osteochondritis and avascular necrosis share?
an area of bone undergoes localised necrosis
what is avascular necrosis?
ischaemic necrosis of bone
predominantly in adults
why can alcoholism, steroid abuse and primary hyperlipidaemia lead to avascular necrosis?
alcoholism and steroid abuse alter fat metabolism and can result in mobilisation of fat into the circulation which can cause ischaemia
primary hyperlipidaemia causes fat to be in circulation as well
what is the treatment of early avascular necrosis? (ie before articular surface has collapse)
drilling under fluoroscopy to decompress bone
prevents further necrosis and helps healing
what is the treatmend of late stage avascular necrosis? (ie articular surface has collapsed)
joint replacement
what does the modified beighton score clinically assess?
if the patient has joint hypermobility syndrome
what do patients with joint hypermobility syndrome usually present with? (if no underlying genetic syndrome)
arthralgia
premature osteoarthritis
what are the 5 signs of inflammation?
rubor (red) calor (hot) dolor (pain) tumor (swelling) functio laesa (loss of function)
what is sequestrium?
dead and dying bone separated from normal bone
a complication of osteomyelitis
what is involucrum?
new bone forming on the outside, just deep to the periosteum
a complication of osteomyslitis
why is pus within a joint an emergency?
pus destroys articular cartilage
why is needle aspiration of a ganglion cyst not recommended?
recurrence is common
what is usually the first clinical sign of hp patholgoy?
loss of internal rotation
what do patients with avascular necrosis of the femoral head present with?
groin pain
what are the late signs of avascular necrosis of the femoral head on radiography?
sclerotic changes
hanging rope sign
irregularity of articular surface
why does a lytic zone form at the neck of a femoral head damaged by avascular necrosis?
lytic zone formed by granulation tissue (attempted repair)
what sign on x-ray suggest avascular necrosis and is due to the lytic zone?
hanging rope sign
what is morton’s neuroma?
irritation of the plantar interdigital nerves (due to repeated trauma) causing neuromas to form
what are neuromas?
swollen and inflamed nerves
what do patients with morton’s neuroma present with?
burning pain and tingling radiating into affected toes
who is more likely to get morton’s neuroma- M or F?
females
which nerves are most commonly affected by morton’s neuroma?
3rd interspace nerve is the most common followed by the 2nd interspace nerve
what test assesses for morton’s neuroma?
mulders test
what is mudlers test?
squeezing the forefoot with your hand
in a positive test symptoms may be reproduced or there will be a characteristic click
what is used for diagnosis of morton’s neuroma?
Ultrasound
what is the conservative management of morton’s neuroma?
metatarsal pad or insole
steroid and local anaethetic injections
what is myositis ossificans?
ossification within a muscle after injury (can be after surgery)
what is pes planus?
loss of the medial longitudinal arch of the foot- flat foot
what is the ligament in the ankle which is most commonly sprained?
ATFL
anterior talofibular ligament
what test assesses whether flat footedness is flexible or stiff?
jacks test- push big toe up
what tendon dysfunction is the most common cause of acquired flatfoot deformity?
tendon of posterior tibialis
what is the primary dynamic stabiliser of the medial longitudinal arch?
tibialis posterior tendon
who tends to get tibialis posterior dysfunction?
obese middle aged females
what pain and swelling is very typical to tibialis posterior dysfunction?
pain/swelling posterior to medial malleolus
what can happen to the big toes in tibialis posterior dysfunction?
can move laterally (hallux valgus)
what type of surfaces do patients with tibialis posteiror dysfunction not life?
uneven surfaces
what can happen to the heel of the foot in tibialis posterior dysfunction?
heel goes into valgus
what can happen to the heel of the foot of a patient with pes cavus?
moves into varus
what are the 4 main causes of plantar fasciitis?
- physical overload (excessive exercise or weight)
- seronegative arthropathy
- diabetes
- abnormal foot shape
what is the main treatment of plantar fasciitis?
conservative: NSAIDs night splint + taping physio steroid injections
how long does plantar fasciitis take to self-limit?
18-24 months
how does the incidence of hallux valgus change with age?
increases with age
is hallux valgus mainly unilateral or bilateral?
bilateral
what are the 5 main problems of hallux valgus?
transfer metatarsalgia lesser toe impingement pain cosmesis of deformity shoe difficulties
why does hallux valgus cause transfer metatarsalgia?
loss of function of big toe
lesser toes are used for power
these toes eventually become sore
what is hallux rigisus?
OA of 1st MTP joint
what is the commonest area for morton’s neuroma and why?
between 3rd and 4th digit (because these are very mobile so are constantly rubbing against each other)
what is the first line treatment for morton’s neuroma?
steroid injections
what type of condition is curly toes?
paediatric condition
if a swelling is ‘fluctuant’, what type of material is within it?
semi-solid material
what is an abscess?
a discreet collectin og pus
what is the management of bursitis? (which hasn’t become secondarily affected)
NSAIDs
analgesia
what is the management of bursitis that has become secondarily affected?
incision and drainage
antibiotics
how many bursae are around the knee?
4 bursae
what actually is the bunion on the medial side of the foot formed by hallux valgus?
an inflamed bursa
why do bouchards and heberdens nodes occur?
chronic trauma
what arthritis are bouchards nodes present in?
OA or RA
what arthritis are heberdens nodes present in?
OA
what is myositis ossificans?
ossificaiton (calcification) of a muscle haematoma
outside the bone, in a muscle
what usually happens before myositis ossificans?
large trauma (haematoma occurs)
when can you intervene with myositis ossificans?
only if symptoms demand
and only once the ossification has matured (otherwise risk of recurrence)
what joints are most commonly affected by OA?
DIP joints
what are mucous cysts?
outpouching of synovial fluid from DIP joints
what condition are mucous cysts associated with?
osteoarthrtis
what is DeQuervain’s tendonitis?
tendonitis of the tendons which control the thumb
when is ficklesteins test positive?
in Dequervain’s tendonitis
in dupuytren’s contractures what do the fibroblasts change in to?
myofibroblasts
what simple test is a way to determine if the dupuytren’s contractures are severe enough to require surgery?
table top test
what is paronychia?
infection within the nail fold (essentially an abscess)
wat is tendinopathy?
disease of a tendon
what is tendonitis?
acute tendon injury accompanied by inflammation
what is tendonosis?
chronic tendon injury with damage to tendon at cellular level
what is tenosynovitis?
inflammation of the tendon sheath
what is enthesopathy?
inflammation of the tendon origin or the insertion
