MSK rheumatology summary Flashcards
autoantibody for mixed CTDs
anti RNP
are ganlion cysts true cysts? why?
no epithelial lining
histology of synovial cysts
space with myxoid material
which drugs may cause dupytrens
anticonvulsants
features of embryonal rhabdomyosarcoma
cildhood
central tract, GI tract, GU tract, H+N, common bile duct
deletion xp11,15
features of alveolar skeletal muscle tumours
young adults
many sites eg H+ N
PAX translocation (t2,5)
features of pleomorphic skeletal muscle tumour
rarest form of older age group
IHC - myogi, myogenin
what is the difference between liposarcoma and lipoma
lipoblasts (purple blobs) in liposarcoma
who are rhabdomyosarcomas found in
children
where are leiomyomas found?
uterus
what is an osteoma
simple - cranial bones
multiple - gardners syndrome
paediatric leisons - nidus
what is an osteosarcoma
childrens long bones
codmans triangle
any malignant osteoid producing tumour is osteosarcoma until proven otherwise
what is ewings sarcoma
translocation of chromosomes 11+12
small, round, blue cells
describe nodular fascitis
a rare, non-cancerous tumour of soft tissue which mimics cancer cells
which cells surround the terminal bouton?
schwann cells
what are the 5 key steps of neuromuscular transmission?
- synthesis of ACH in cytoplasm of bouton
- uptake of ACH into synaptic vesicles for concentration + storage
- Ca+ dependent release of ACH INto synaptic cleft by exocytosis
- brief activation of nicrotinic ACH receptors by reversible binding of ACH
- rapid transmission of neurotransmittion action by ACHe within synaptic cleft
what is the role of ACHe?
it hydrolyses ACh to choline + acetate
- choline is taken up by choline transporter
- acetate diffuses from synaptic cleft
what is neuromytonia / issacs syndrome?
cramping, stiffness + muscle twitches
prolonged epp
how to treat isaacs syndrome?
carbimazepine (blocks voltage gates Na+ channels)
what is lambert eaton myasthenia syndrome?
muscle weakness in limbs
associated with SCLC
decreased release of ACH
how to treat lambert eaton mtasthenia syndrome?
pyridostigmine (increases duration of action of ACH in synaptic cleft + K+ channel blockers
what is myasthenia gravis
increasing muscle weakness during periods of activity
weakness in eyelid and muscles
decreased epp
how to treat myasthenia gravis
pyridostigmine
what it botulinum toxin
irreversively inhibits ACh release
used to remove wrinkes
what is an osteochondroma
most common cartilaginous outgrowth local pain 1% chance of malignancy multiple = MEN
what is an enchondroma
intramedullary
metaphyseal cartilaginous tumour
what causes enchondroma
failure of normal enchondral ossification at the growth plate (growing cartilage is replaced by bone)
what does enchondroma look like
a leucent lesions which can undergo mineralisation –> patchy sclerotic appearance
what is a simple bone cyst
fluid fillled cyst in bone
growth defect from physis
where are simple bone cysts usually seen?
proximal humerus and femur
what is a giant cell tumour
locally agressive / painful
involves epiphysis
where are giant cell tumours most commonly seen
knee and distal radius
soap bubble appearance
what is the met stat for giant cell tumor?
5% met to lung
how to treat giant cell tumour
intralesional excision with phenol, bone cement or liquid nitrogen to destroy remaining tumour
what if fibrous dysplasia?
genetic mutation which causes lesions of fibrotic tissue + immature bone
what is xray sign for fibrous dysplasia?
extensive involvement of femur = shephards crook deformity
what does a bone scan show in fibrous dysplasia?
increased uptake during development but usually becomes inactive
what is the treatment for fibrous dysplasia?
bisphosphonates
what is osteoid osteoma?
small nidus of immature bone surrounded by an intense sclerotid halo
features of osteoid osteoma?
intense constant pain which is worse at night
NSAIDS
what is an osteosarcoma?
produced bone in adolescents
60% around knee
met spread - haematogenous
met stats for osteosarcoma
10% have pulmonary mets at diagnosis
what is a chondrosarcoma
cartilagous producing bone
older ages - 45
large and slow to met
pelvis / proximal femur
what is a fibrosarcoma
occurs in abnormal bone eg bone infarct
what is ewings sarcoma
primitive cells in bone marrow
fever
warm swelling
treatment of primary malignant bone tumours
- bone scan / CT/ MRI -> local extent of tumour
- biopsy - histology and grading
- bone removed with wide margin of 3-4cm of bone + a cuff of normal muscle all around
- adjuvant radio / chemo if indicated
describe breast bone mets
can be blastic /sclerotid (fills bone with extra cells)
or lytic (destroy bone material)
24-26 months survival
describe prostate bone mets
sclerotic mets
more likely to hear
45% survival at one year
describe lung bone mets
lytic bony mets
6 months survival
describe renal cell carcinoma bone mets
vascular ‘lyric blow out’ bony mets
can bleed with biopsy / surgery
12-18 months
what is a bursa?
small fluid filled sac lined with synovium around a joint which prevents friction between tenodons, muscles and bones
causes of AVN
alcohol + corticosteroids (they alter metabolism > coagulation > ischaemia + Stasis)
thrombophila
caissons disease
genetics for RA
HLA DR4
HLA DRB1
arginine > citrulline > protein unfolding due to loss of positive charge (anti-CPP)
which joints are affected by RA?
MCP, MTP, PIP
small joints before bigger joints
what is atlanto axial subluxation?
a symptom of RA
occurs due to destruction of the synovial joint between atlas + dens + rupture of transverse ligaments
what is the occular involvement of RA?
keratoconjunctivitis sicca
episcleritis
uveitis
nodular scleritis (may lead to scleromalacia)
what cytokine production is involved in RA?
INFg - activated synovial cells
TNF + IL1 - stimulates production of proteases from synovium
RANKL on activated T cells - stimulates bone resorption
how does rheumatoid factor work?
IgM or IgG antiobody binds to Fc region of IgG
acute vs chronic phase of RA?
acute - pannus formation + Destroyed cartilage
chronic - fibrosis + deformity
can anti CPP be present before symptoms?
yes and remains positive during treatment
which scoring system is used for RA?
das 28
explain results of das28
<2.6 - remission
2.7-3.2 - decreased disease activity
3.3-5.1 - moderate disease activity
>5.1 - increased disease activity
side effects of DMARDs
bone marrow suppression infection liver fucntion derangements pneumonitis nausea takes 3 months to start working
give example of anti TNF
infliximab
give example of b cell depleter
rituximab
give example of IL6 blocker
toclizumab
decsribe swan neck deformity
volar plate of PIP joint becomes attenuated
small ligaments + lubrical tendons fall more dorsal to joint centre
describe boutonniere button hole
extensor hood of PIP joint becomes attenuated
flexion of PIP
what is the stepwise treatment for RA?
- non-opioid eg NSAID
- weak opioid eg codine + NSAID
- strong opioid (morphine) + non-opioid
what virus is associated with SLE
EBV
is ANCA + or - in SLE
+
minor features of SLE
sclerodactylyl
atrophy or fingertips
bilateral lung fibrosis
haematological features of SLE
anaemia
leukopenia (decreased WCC)
thrombocytopenia (decreased platelets)
renal features of SLE
proteinuria >0.5g in 24 hours
random features of SLE
jaccouds arthroplasty + serosis
diagnosis of SLE
1 major and 2 micro
management of SLE
HLQ (DMARD)
3 stages of raynauds
blanching > acrocyanosis > reactive hyperaemia
antibodies involved with scleroderma
anticentromere (limited)
anti-scl70 (diffuse)
anti-RNA polymerase
treatment for pulmonary hypertension
PDE5 inhibitor
what is pulmonary fibrosis
progressive SOB
bilateral crackles on chest examination
restrictive pattern
treatment of pulmonary fibrosis
- mycophenolate mofenl
2. rituximab
which antibody is associated with renal crisis?
anti RNA polymerase 3 antibody
3 features of dermatomyositis
gottrons papules (red marks on knuckles) helitropes rash (red/ purple rash around eyelids) shawl sign - rash in shawl area
does polymyositis increase CK
yes
diagnosis of poly / dermatomyositis
- perivascular inflammation + muscle necrosis
2. MRI - muscle inflammation, oedema, fibrosis + calcification
treatmetn for poly / dermato myosiits
- corticosteroids
2. immunosuppression
treatment of polymyalgia rheumatic
15mg prenisolone
treatment of temporal arteritis / giant cell arteritis?
40-60mg prednisolone (gradulal reduction over 2 years)
feature of fibromyalgia
widespread pain > 3 months
grading for ankylosing spondylititis
modified new york critera + ASAS classification
xray features of psoriatic arthritis
marginal erosions
whiskering
pencil in cup
when does reactive arthritis occur?
1-4 weeks after infection
how to treat recative arthritis ?
NSAIDS
feature of enteropathic arthritis
pyoderma gangrenosum
symptoms of large vessel vasculitis
bruit (carotid artery)
BP differences of extremities
claudication
who gets takaysu
<40 asian females
who gets giant cell arteritis
> 50
associated with polymyalgia rheumatic
risk of blindness
how to treat giant cell arteritis
40-60mg prednisolone
symptoms of GPA
nasal / oral inflammation
abnormal chest radiograph
urinary sediment
grnaulomatous inflamamtion on biopsy
who gets GPA
35-55
symptoms of EGPA
late onset asthma + increased eosinophil count
10% increase in peripheral blood
symptoms of HSP
bloody diarrhoea
purpura
2-11 years olds after URTI
