pathology Flashcards
name types of arthritis
osteoarthritis rheumatoid arthritis seronegative spondyloarthropathies infective arthritis crystal induced arthritis
what are different types of seronegative spondyloarthropathies
Ankylosing spondylitis
Reactive arthritis, Enteritis associated arthritis
Psoriatic arthritis
what joints does arthritis focus on
synovial joints
primary cause of osteoarthritis
insidious
no cause
age related
secondary causes of osteoarthritis
predisposing condition
excess weight bearing, deformity injury, systemic conditions
features of osteoarthritis
aches and pains
usually hips, knees, lower lumbar and cervical vertebrae, PIP and DIP joints on fingers
pathogenesis of osteoarthritis
degeneration of the cartilage and disordered repair
injury to chondrocytes and matrix
stimulate inflammatory changes in synovium and subchondral bone
repetitive injury and chronic inflammation
presentation of rheumatoid arthritis
malasie, fever
msk pain
joint involvement - swollen, pain, warm
small joints before large joints
progression of rheumatoid arthritis
Joint swelling, Decreased range of movement, Joint fusion (ankylosis)
Associated involvement of tendons and ligaments
Joint deformity
Unstable, (very) limited ROM
Synovial herniation – cysts eg Baker’s cyst
Joint effusions, peri-articular bone loss, loss of articular cartilage
what does IFNg activate in rheumatoid arthritis
macrophages and synovial cells
what does IL-17 recruit in rheumatoid arthritis
neutrophils and monocytes
what does TNF and IL-1 stimulate production of in rheumatoid arthritis
proteases from synovium
RANKL in rheumatoid arthritis
expressed on activated T cells and stimulates bone resorption
what autoantibody in rheumatoid arthritis
IgM or IgA
what are the acute phases of rheumatoid arthritis
pannus formation
hyperactive/reactive synovium
what is potential extra-articular manifestations in rheumatoid arthritis
rheumatoid nodules
small vessel vasculitis
pyoderma gangrenosum
features of ankylosing spondylitis
destructive arthritis
sacro-iliac and intervertebral joints
bony ankylosis
two forms of crystal arthropathy
gout - urate metabolism
pseudo-gout - calcium pyroposphate
synthesis of hyperurucaemia
from purine catabolism
reflects abnormal purine metabolism
excretion of hyperurucaemia
renal filtration
resorbed in proximal tubule
limited excretion from distal tubule
what happens in osteoporosis
decreased bone mass
risk of fracture
what bone mass indicates osteopenia
1-2.5 SD
what bone mass indicates osteoporosis
> 2.5 SD
causes of secondary osteoporosis
endocrine disorders
GI disorders
drugs
miscellaneous - immobilisation
main causes of osteoporosis
- age related
- reduced physical activity
- genetic factors
- calcium
- hormonal effects
how does old age cause osteoporosis
reduced proliferation and biosynthetic capacity of osteoblasts
response to growth factors attenuated
what hormonal effects can cause osteoporosis
- post-menopausal
- low oestrogen causes high bone turnover
- monocytes release inflammatory mediators
cause of osteomalacia
vit D deficiency
what can vit D deficiency lead to
hypocalcaemia and PTH elevated
what happens in osteomalacia
impaired mineralisation of bone matrix
- bone remodelling
- thick osteoid seams
- bone is weakened
what is avascular necrosis
- necrosis of bone and marrow
- the result of loss of effective vascular supply
predisposing factors for AVN
- alcohol
- corticosteroids, bisphosphonates
- connective tissue disorders
- decompression
- sickle cell disease
- infection, pregnancy, pancreatitis, radiation
what does parathyroid hormone do
- activates osteoclasts
- increased resorption of calcium by renal tubules
- increased urinary phosphate excretion
- increased synthesis of active forms of vit D
what can hyperparathyroidism cause
- continued osteoclasis
- osteoporosis
- brown tumours
- osteitis fibrosa cystica
what is a brown tumour
mass of reactive tissue in osteoporotic bone prone to tumour
what is Paget’s disease of bone
abnormality of bone turn-over
-osteitis deformans
what are the three stages of Paget’s disease
- osteolytic
- mixed
- osteosclerotic
what happens in osteolytic stage
resorption pits with large osteoclasts
what happens in the mixed stage
osteoclasis and osteoblastic activity
what is the net result of paget’s disease
thick excess bone with abnormal reversal lines
characteristic of soft tissue lesions
- present as lump or swelling
- pain and discomfort
- wide range of lesions
what is a ganglion cyst
- lump near joint or tendon sheath
- common at wrist
- degenerative change with connective tissue
- no epithelial lining
- secondary inflammatory changes
what is nodular fasciitis
-fast growing lump in soft tissue
-self limiting
disorder
-cellular proliferation of fibroblastic and myofibroblastic cells
-young adults
what is myositis ossificans
- history of trauma
- insertions of large muscles of arms and legs
- cellular proliferation but with evidence of bone formation and zonation
what is superficial fibromatoses
- non cancerous tumour
- common
- Dupuytren’s
- 60 yrs
- idiopathic
what is Dupuytren’s
- thickening of the skin on your hand (palms)
- firm grey-white tissue
- nodules and fascicles
- bland fibroblasts
- dense collagen
what is deep fibromatosis
- desmoid tumour
- large infiltrative masses
- do not metastasise
what is tenosynovitis
- giant cell tumour of tendon sheath
- digits and wrist
- reactive proliferations
- pigmented villonodular synovitis
name benign tumours
Lipoma Haemangioma Leiomyoma Rhabdomyoma Chondroma Osteoma Neurofibroma / Schwannoma
name malignant tumours
Liposarcoma Angiosarcoma Leiomyosarcoma Rhabdomyosarcoma Chondrosarcoma Osteosarcoma Neurofibrosarcoma / MPNST
what are tumours derived from fat called
benign - lipomas
malignant - liposarcoma
what are tumours derived from smooth muscle called?
leiomyomas
what are tumours derived from skeletal muscle called
rhabdomyomas
examples of benign tumours that arise from cartilage
- enchondroma
- osteochondroma
- chondromyxoid fibroma
what is a chondrosarcoma
a malignant tumour that produces cartilage
- bulky tumour
- nodules of grey/white cartilaginous tissue with gelatinous matrix
- locally invasive in bone and into muscle and fat
what are the three types of chondrosarcoma
- dedifferentiated chondrosarcoma
- clear cell chondrosarcoma
- mesenchymal chondrosarcoma
where are simple osteomas found
cranial bones
what is Gardner’s syndrome
multiple simple osteomas
where are osteosarcomas found
long bones
-usually in children
what is any malignant tumour that produced osteoid called? (unless proven otherwise)
osteosarcoma
characteristics of Ewing’s sarcoma
- children and adolescents
- any soft tissue or bony location
- destructive, rapidly growing and highly malignant
name some causes of a pathological fracture
- osteoporosis
- tumours
what does osteolytic mean
bone is resorbed and appear as radiolucent
