Week 1 Flashcards
commonest benign bone tumour
osteochondroma
what do osteochondroma consist of
bony outgrowth on the external surface with a cartilaginous cap
sign/symptoms of osteochondroma
local pain
what is an enchondroma
intramedullary and usually metaphyseal cartilaginous tumour caused by failure of normal enchondral ossification at the growth plate.
how does an enchondroma appear
lesion usually lucent
can undergo mineralisation with a patchy sclerotic appearance
weaken the bone resulting in fracture
features of enchondroma
many are indcidental findings
can occur on femur, humerus, tibia and small bones of hand and feet
what is a simple bony cyst
single cavity benign fluid filled cyst in bone
where a simple bony cysts seen
in long bones and in talus or calcaneus
features of simple bony cyst
asymptomatic
incidental finding
weakness can lead to fracture
how are simple bony cysts and enchondroma treated
curettage
bone grafting
what is an aneurysmal bone cyst
lots of chambers which are filled with blood or serum
where can aneurysmal bony cysts occurs
metaphyses of many different long bones, flat bones (ribs, skull) and vertebral bodies
signs/symptoms of aneurysmal bony cysts
locally aggressive causing cortical expansion and destruction
painful
where do giant cell tumours affect
epiphysis and can extend to the subchondral bone
where are GCTs commonly found
knee
distal radius
pelvis
spine
signs/symptoms of GCT
painful
can cause pathological fracture
consists of multi-nucleate giant cells
x-ray ‘soap bubble’ sign
what is fibrous dysplasia
disease of bone where a genetic mutation results in lesions of fibrous tissue and immature bone.
features of fibrous dysplasia
can be mono or polyostotic
causes angular deformities
affected bone is wider with thinner cortices
stress fractures can occur
what does Extensive involvement of the proximal femur in fibrous dysplasia cause
shepherd’s crook deformity
what is an osteoid osteoma
small nidus of immature bone surrounded by an intense sclerotic halo.
occur in teens
where do osteoid osteoma occur
proximal femur, the diaphysis of long bones and the vertebrae
symptoms/signs of osteoid osteoma
intense constant pain, worse at night due to the intense inflammatory response
what is the most common malignant bone tumour, who and where does it most commonly affect
osteosarcoma
younger age groups
knee
what can prolonged survival in osteosarcomas
radiotherapy then chemotherapy
what is a chondrosarcoma
cartilage producing primary bone tumour
tends to occur in older age groups
features of chondrosarcoma
very large, slow to metastasise
found in pelvis or proximal femur
what is Ewing’s sarcoma
tumour of primative cells in the marrow
poorest prognosis
occur between 10-20 y/o
what is Ewing’s sarcoma associated with and what is it sensitive to
associated with fever, raised inflammatory markers and a warm swelling
radio and chemo sensitive
treatment of ES
surgery to remove the tumour and surrounding tissue to reduce the risk of recurrence
amputations common
what do breast cancer mets appear as
blastic (sclerotic) or lytic
what do prostate cancer mets appear as
sclerotic
what do lung cancer mets appear as
lytic bony metastases
what do renal cancer mets appear as
large and very vascular lytic “blow out” bony metastases
what are features that suggest benign soft tissue neoplasm
smaller size, fluctuation in size (malignant tumours don’t regress in size), cystic lesions, well‐defined lesions, fluid filled lesions and soft / fatty lesions
what are features that suggest malignant soft tissue neoplasm
larger lesions (>5cm), rapid growth in size, a solid lesion, an ill‐defined lesion, an irregular surface, associated lymphadenopathy and systemic upset (weight loss, loss of apetite, fatigue).
first line investigation for suspicious swelling
MRI
what is the commonest benign soft tissue swelling
lipoma - neoplastic proliferation of fat
large but may not be well defines
where do ganglion cysts occur
around a synovial joint or a synovial tendon sheath
may form as a result of herniation or out‐pouching of a weak portion of joint capsule or tendon sheath
features of ganglion cysts
well‐defined, may be quite firm and readily transilluminate
can be excised but don’t need to be
what is bursitis
inflammation of bursa around a joint
what causes bursitis
repeated pressure or trauma
may present as a soft tissue swelling
what causes a burial abscess
bacterial infection
what is AVN
ischaemic necrosis of bone
what are causes of AVN
idiopathic alcohol/steroid abuse thrombophilia sickle cell disease antiphospholipid deficiency in SLE
AVN can cause secondary osteoarthritis - true or false
true
what is osteoporosis characterised by
reduced bone mineral density and increased porosity
i.e. bone is of normal quality there is just not enough of it
what does WHO define osteoporosis as
bone mineral density less than 2.5 standard deviations below the mean peak value of young adults of the same race and sex
what is osteopenia
intermediate stage where bone mineral density is between 1 to 2.5 standard deviations below mean peak value
risk factors for osteoporosis
menopause smoking alcohol abuse lack of exercise poor diet
how is bone disease diagnosed
DEXA scan
what are the serum calcium and phosphate levels in osteoporosis
normal
Tx for osteoporosis
Calcium and vitamin D supplements
Bisphosphonates
HRT - last line
what is osteomalacia
abnormal softening of the bone due to deficient mineralization of osteoid (immature bone) secondary to inadequate amounts of calcium and phosphorus
what is osteomalacia called in children
Rickets
what is the two primary causes of osteomalacia/rickets (biochemistry)
1 - insufficient calcium absorption from the intestine because of lack of dietary calcium or a deficiency of or resistance to the action of vitamin D
2 - or phosphate deficiency caused by increased renal losses.
what are diseases/conditions that cause osteomalacia/rickets
malnutrition malabsorption lack of sunlight exposure hypophosphateamia (alcohol abuse) CKD
Sx of osteomalacia/rickets
Bone pain
Deformities of soft bones
Sustain fractures easily
Sx of hypocalcaemia (e.g. paraesthesiae, muscle cramps, irritability, fatigue, seizures, brittle nails)
what is seen on x-rays of osteomalacia
pseudofractures e.g. Looser’s zones
biochemistry results of osteomalacia
low calcium
low serum phosphate
high serum alkaline phosphatase.
Tx of osteomalacia
vitamin D therapy with calcium and phosphate supplementation
biochemistry of primary hyperparathyroidism
Serum PTH is usually elevated Calcium is high.
Phosphate is normal or low
what is secondary hyperparathyroidism
overproduction of PTH secondary to hypocalcaemia usually caused by vitamin D deficiency or CKD
