Pathology Flashcards
What is secondary vasculitis?
when vessels become inflamed as they are in proximity to inflam eg vessels beside the appendix which get inflamed during appendicitis
What is infection vasculitis?
when there is direct invasion of the vessel by pathogens and therefore inflammation of the vessel wall eg syphilis
What causes immune mediated vasculitis?
immune compex deposition and speciif antibodies (anti-endothelial)
What does ANCA stand for?
anti-neutrophil cytoplasmic antibodies
What is the difference between pANCA and cANCA?
p stnads for perinculear and just binds around nucleus whereas c stands for cytoplasmic and antibodies are diffuse throughout the cytoplasm
How is vasculitis classified?
by the size of vessels affected- large, medium or small
What is an example of large vessel vascultiis?
giant cell arteritis
What is seen on biopsy of giant cell arteritis?
granulomas in the media of the vessel with the elastic fibres almost completely obliterated- segmental with skip lesions
What is the signifance of skip lesions in biopsies?
a negative biopsy doesnt rule out as might hve biopsied okay area
What are the symptoms of giant cell arteritis?
affects temporal artery- temporal headache jaw claudication, scalp tenderness, blindness
What is the treatment for giant cell arteritis?
steroids
Why dont you get rashes with large vessel vasculitis?
big vessels arent near the skin
What type of vasculitis of polyarteritis nodosa?
medium vessel
Why is PAN thought to be caused by circulating immune complexes?
1/3rd of pts have hepB positivity with circulating immune compexes and antibodies
What is seen on biopsy of PAN?
transmural necrotising inflam- fibrinoid necrosis of vessel
What organs are affected in PAN?
kidneys- spares lungs (unusual)
What are the small vessel vasculitis?
Wegeners-granulomatosis with polyangiitis
Churg Strauss-eosinophilic granulomatosis
Henoch Schonlein Purpura
Cryoglobulinaemia
Goodpastures
What is crystal arthropathy?
gout
What is the cause of gout?
build up of urate and uric acid - end products of purine synthesis (adenine and guanine are purine based) so urate is formed in DNA replication etc.
What are the 2 pathways that can cause hyperuricaemia?
making too much or etting rid of too little
What can cause making too much urate?
usually idiopathic (unkown enzyme defect) known genetic defect increased cell turnover- cancer; psoriasis; tumour lyssi with chemo
What is the most common cause of gout?
under-excretion
What is a common drug that reducing urate excretion?
thiazide diuretics
Why does uric acid end up joints?
moves around and then crystallises in joints due to the lower temperatures there
What happens when uric acid is depostied in joints?
crystals stimulate an inflammatory response which causes damage
What does uric acid cause in the kidney?
stones and direct deposition in the tubules
What do the uric acid crystals look like?
needle-shaped crystals; show negative birefringence
What does negative birefringence mean?
crystals bend the light twice at a negative angel
What causes pseudo gout or chondrocalcinosis?
calcium pyrophosphate
what can cause psuedogout?
usually idiopathic but- hypercalcaemia (inc. hyperparathyroidism); haemachromatosis; hypomagnesia
What is the difference between the crystals in gout and pseudogout?
gout- negative bifringence whereas pseudogout-weak positive birefringence, crystals are thicker and bigger, rhomboid shape
What is Paget’s disease?
abnormality of bone turnover
What causes Paget’s?
increase osteoclastic activity which causes more bone but not normally structured
What causes Paget’s?
genetics, viral infections
What is the difference pathologically between Paget’s and normal bone?
normal bone is v. organised- looks like rings in trees whereas in Paget’s there is thick excess bone with abnormal mosaic pattern
What causes pain in Pagets
microfractures and nerve compression
What bones does Paget’s mainly affect?
axial bones
What does increased metabolism mean in terms of presentations?
heat, warm skin, AV shunt and high output HF
What secondary malignancy can Pagets cause?
osteosarcoma
What causes osteomalacia?
abnormal vitamin D metabolism (adult version of rickets) due to reduced sun exposure
What are the symptoms of osteomalacia?
bowed legs, square heads, pigeon chest, rickety roasry
What is a pathological fracture?
fracture is out of keeping with level of trauma
What are the initatal phases of fracture healing?
haematoma creates a fibrin mesh, there is influx of infllam cells which release cytokines-recruit osteoprogenitors from periosteum and medullary cavity
What is formed after 1 week in fracture healing?
callus and organised haematoma
What is seen at 2-3 weeks post fracture?
maximum girth of callus; woven bone deposited perpendicular to cortical bone some cartilage depostion at fracture site which undergoes endochondral ossification- bridigin witha bony callus
Why is it important to move around after a fracture?
so that bone can remodel in response to correct stresses
What can cause delayed healing?
poor blood supply and nutrition- can be caused by lots of soft tissue injury around fracture
What are the big 4 areas that bone mets come from??
lung, kidney, breast and prostate
What is different about the appearance of prostate mets on film compared to the majory?
met appears as an area of opacity rather than radiolucent as prostate is osteosclerotic rather than osteolytic
What causes avascular necrosis?
bone infarction- alcohol; trauma etc etc
How does avascular necrosis appear?
wedged shaped infarct with creeping substitution (substituting infarcted dead bone with new bone)
What happens to the joint in osteoarthritis?
small cracks in cartilage until eventuallteh cartilage is completely worn away and there is bone on bone, bone surface becomes polished eburnation. cortical bone thickens greatly to cope with load and remodelling is disorgansied and produces abdnormal outgrowths-osteophytes
What causes subchondral cysts?
fractures in bone due to disorganised bone growth, synovial fliud leaks through bone forming small cysts
What are the features seen on x-ray of osteoarthritis?
loss of joint space; subchondral sclerosis; subchondral cysts; osteophytes
What is subchondral sclerosis?
eburnation etc
What is an osteochondroma?
cartilage capped bony projection arising on external surface of bone containing a marrow cavity that is continuous with that of the underlying bone
Who does osteochondroma affect?
affects males and females equally, affects the under 20s
Where do osteochondromas tend to occus?
develop near the epiphyses of long bones
What is an enchondroma?
benign hyaline cartilage tumour arising in medullary cavity
Where does enchomdroma tend to occur?
hands and feet
Who does enchonroma occur in?
young adults, males more than females
What is Ollier’s disease?
a rare deleveopmental disorder where there are unilateral enchondromas; malignant transformation- 10-25%
What is Maffucci’s Syndrome?
multiple enchondromatosis with soft tissue and visceral haemangiomas
What is osteoid osteoma?
benign osteoblastic tumour
Who is osteoid osteoma foudn in?
children adn young adults; males more than females
Where are osteoid osteomas found?
femur; tibia; hands/feet and spine
What is seen on pathology of osteoid osteoma?
central core of vascular osteoid and peripheral zone of sclerotic bone
What is seen on presentation of osteoid osteoma?
dull pain that is much worse at night
pain is releived by NSAIDs/aspirin- produces prostaglandins
What is a chondroblastoma?
a benign cartilage tumour arising in bone
Where are chondroblastomas found?
epiphysis of long bones
What age group is affected by chondroblastomas?
people in their 20s
What is the treatment for chondroblastomas?
biopsy and curretage plus adjuvant liquid nitrogen
What is the cell of origin presumed to be in giant cell tumours?
osteoclasts
Who are giant cell tumours seen in?
25-40 year olds; F>M
Where are giant cell tumours seen?
long bones, often around knee
What is an osteoblastoma?
solitary, benign and self-limited tumour that produces osteoid and bone
Where are osteoblastomas found?
metaphysis or diaphysis of long bones
What is seen on histology of osteoblastoma?
irregular spicules of mineralised bone adn osteoid suurounded by osteoblasts
How are osteoblastoma treated?
curettage; intralesional excision and enbloc resection
What is the prognosis ofr osteoid osteoma?
will resolve without treatment in around 33months
What is seen histopathologically in chondroblastoma?
closely packed polygonal cells plus areas of immature chondroid; mitotic activity low; distainct cytoplasmic borders with foci of “chicken-wire” calcification
What is seen on histology of giant cell tumours?
multinucleated giant cells in a sea of roudn to oval mononuclear cells
What is a chordoma?
very rare benign tumour arising from notochord remnants (midline tumour, often sacral region)
Who does chordoma arise in?
occurs in 40+; M:F is 1:2
What is the treatment for chordoma?
resection is difficult; radiation; chemo for late stage
What is the commonest primary malignant tumour of bone?
osteosarcoma
What are the cells of origin in osteosarcoma?
malignant osteoblasts forming osteoid
who does osteosarcoma affect?
young adults; older patients tedn to have predisposing condition- eg Paget’s; M:F is 3:2
Where does osteosarcoma affect?
ends of long bones particularly distal femur; proximal tibia and proximal humerus
What are seen on histology of osteosarcoma?
osteoid production; nuclear stypia; hyperchromasia and a high mitotic rate
What is the treatment for osteosarcoma?
pre-op chemo; surgical resection; post-operative chemo
What is the second commonest primary malignant tumour of bone?
chondrosarcoma
What is chondrosarcoma composed of?
malignant chondrocytes
What is seen on histopathology of chondrosarcoma?
malignant nodules of chondrosarcoma infiltrate between the lamellar bone oblierating the marrow; separation of the nodules by fibrous bands would also be highly suggestive
What is the treatment for chondrosarcoma?
wide srgical excision
Where does Ewing’s Sarcoma occur?
occurs in the metaphysis and diaphyssi of femur; tibia then humerus
Who gets Ewing’s Sarcoma?
most common in teens; M:F is 3:2
What is the treatment for Ewing’s sarcoma?
surgery; radiation; chemo
Where are the common sites of primary origin of bone mets?
thyroid; breast; lung (small cell); kidney; prostate
What is multiple myeloma?
malignant proliferation of plasma cells in bone marrow
Who gets multiple myeloma?
old peopl
What the side effects of multiple myeloma?
renal failure; bone destruction of axial skeleton
