Cortex- pathology, biochemistry, histology Flashcards
what are the possible causes if benign bone tumours
neoplastic, developmental, traumatic, infection or inflammatory
what is the most common benign bone tumour
osteochondroma
what does an osteochondroma look like
bony outgrowth on the external surface with a cartilaginous gap
what are the symptoms of osteochondroma
non usually, can cause local pain
when should osteochondromas receive treatment and what treatment)
1% risk of malignant transformation
any lesion growing in size or producing pain may require excisional biopsy
what can cause multiple osteochondromata
autosomal dominant hereditary disorder
what is an enchondroma
an intermedullary and usually metaphyseal cartilagenous tumour
what causes an enchondroma
failure of normal enchondral ossification at the growth plate
what do enchondromas look like
usually lucent, can undergo mineralisation with a patchy sclerotic appearance
what is the risk of an enchodroma
can weaken the bone resulting in pathological fracture
where so enchondromas commonly occur
in the femur, humerus, tibia and small bone of the hands and feet
how do you strengthen a bone with an enchondroma
curettage the tumour and fill with bone graft
what is a simple bone cyst (aka unicameral bone cyst)
a single cavity benign fluid filled cyst in a bone
what causes a simple bone cyst
growth defect from the physis
where do you get simple bone cyst
(as growth defect in physis) metaphyseal in long bones (proximal humerus and femur), can also occur in the talus or calcaneus
why is curattage with a bone graft a possible option for a simple bone cyst (+/- stabilisation)
as it may weaken bone causing pathological fracture
what is an aneurysmal bone cyst
lots of chambers filled with blood or serum
where do you get aneurysmal bone cysts
can occur in the metaphyses of long bones, flat bones (ribs, skull) and vertebral bodies
what are the risks with an aneurysmal cyst
they are locally aggressive, cause cortical expansion and destruction and usually pain. risk of pathological fracture
what is the treatment for aneurysmal cysts
curattage and bone graft/ bone cement
where do you get giant cell tumours
metaphyseal and epiphysis regions, can extend to subchondral bone adjacent to the joint
commonly occur around knee, and in the distal radius, other long bones, pelvis and the spine
what is the risk of giant cell tumours
can be locally aggressive, destroy cortex, painful, can cause pathological fracture, 5% can metastasise to the lung (still considered benign)
what are the benign bone tumours
osteochondroma, enchondroma, simple and aneurysmal bone cyst, giant cell tumour, fibrous dysplasia, osteoid osteoma, brodies abscess
when do giant cell tumours occur
after the physis has fused
what is the histology of giant cell tumours
multinucleated giant cells
what do giant cell tumours look lie on x ray
soap bubble appearance
what is the treatment for a giant cell tumour
intalesional excision with use of phenol, bone cement or liquid nitrogen to destroy remaining tumour material (reduce the risk of recurrence)
if very aggressive lesion which has destroyed cortical then may need joint replacement
what are the reg flags of bone cancer
constant pain, usually severe and at night, weight loss, fatigue, loss of appetite
(all unexplained skeletal pains should be investigated- at least an x-ray)
what age does bone cancer occur
can happen at any age
what do malignant primary bone cancers look like on x rays
aggressive and destructive signs: cortical destruction, a periosteal reaction (raised periosteum producing bone), new bone formation (sclerosis as well as lysis from destruction), extension into the surrounding soft tissue envelope
what is the most common form of primary bone tumour
osteosarcoma
who usually gets osteosarcoma and where
younger age groups (adolescence and early childhood) 60% involving bones around the knee.
also seen in proximal femur, proximal humerous and pelvis
what is the usually method of bone cancer metastasis
haematogenous, can also be lymphatic
how many patient have metastasis at diagnosis
10%
what is the role of chemo in bone cancer treatment
not radiosensitive adjuvant chemotherapy can prolong survival
what is a chondrosarcoma
a cartilage producing primary bone tumour
how does a chondrosarcoma compare to an osteosarcoma
less common and less aggressive
occurs in older age groups
where do you get chondrosarcoma and what are they like
in pelvis or proximal femur
large and slow to metastasise
what chemo does chondrosarcoma respond to
none
what are fibrosarcomas and malignant fibrous histiocytoma
fibrous malignant primary bone tumours
what are the malignant primary bone cancers
osteosarcoma, chondrosarcoma, fibrosarcoma, malignant fibrous histiocytoma, ewing’s sarcoma
(+ lymphoma and myeloma)
who an where do fibrosarcomas and malignant fibrous histiocytomas occur
in abnormal bone (bone infarct, fibrous dysplasia, post irradiation, paget’s disease
in adolescent or young adults usually
what is ewings sarcoma
malignant tumour of primative cells in the marrow (2nd most prevalent)
what bone cancer has the poorest prognosis
ewings sarcoma
who gets ewings sarcoma
most cases between ages 10 and 20
what are the symptoms of ewings sarcoma
fever, raised inflammatory markers and a warm swelling (may be misdiagnosed as osteomyelitis)
does ewings sarcoma respond to chemo and radio
is chemo and radio sensitive
what is the treatment for primary bone tumours
usually involves surgery to remove the tumour and surrounding tissue to reduce risk of recurrence
adjuvant therapies and neo-adjuvant therapy prior to surgery
what staging investigations should be done for bone cancer
bone scan, CT chest, MRI, biopsy
what is lymphoma
cancer of the cells of the lymphatic system/ macrophages
can occur as primary bone tumour
what is hodgkins lymphoma
type of lymphoma arising from lymphocytes
where does primary lymphoma of the bone usually affect and what is the treatment
the pelvis or the femur
surgical resection
what are signs of metastatic lymphoma and what is the treatment
lymphadenopathy and splenomegaly
chemotherapy and radiotherapy
what is the usual survival for metastatic lymphoma
less than 2 years
what is a myeloma
a malignant B cell proliferation, arises from the marrow
how can myeloma present
as a solitary lesion (plasmacytoma) or with multiple osteolytic lesions throughout the skeleton (multiple myeloma)
patients may present with pathological fracture
what are the symptoms of multiple myeloma
patients usually 45-65
weakness, back pain, bone pain, fatigue and weight loss, marrow suppression resulting in anaemia and recurrent infection
how do you diagnose myeloma
plasma protein electrophoresis, early morning urine collection for bence jones protein assay
what are the treatments for plasmacytoma and multiple myeloma
plasmacytoma- radiotherapy
multiple myeloma= chemotherapy
list 5 primary malignant tumours which commonly metastasise to bone
(all carcinoma except thyroid) breast prostate lung renal thryroid adenocarcinoma
describe the bone metastasis of breast and its survival
can be blastic (sclerotic) or lytic
survival 24-26 months
describe the bone metastasis of prostate cancer, treatment and survival
produces sclerotic metastases
radiotherapy and hormone manipulation can reduce fracture risk
survival 45% at one year
describe the bone metastasis and survival of lung caner
lytic bony metastases
6 months
describe the bone metastasis, treatment and survival of renal cell cancer
potentially large an very vascular lytic blow out boney metastasis
with a single bony metastasis amenable to resection (nephrectomy) surgery can be curative
multiple bone metastases survival is 12-18 months
what bones are commonly involved in metastasis
vertebra, pelvis, ribs, skull, humerus and long bones of lower limb
if metastasis is suspected, what tests should be done
breast/ PR exam
CXR may detect a pulmonary lesion
blood tests: serium calcium (hypercalcaemia), LFTs (liver mets), plasma protein electrophoresis (for myeloma), FBC and U&Es
when might joint replacement or skeletal stabilisation be required
painful lesions
those that occupy >50% of diameter of bone
those with cortical thinning
those in risk of impeding pathological fractures
what are the two forms of sift tissue swelling
diffuse (e.g. synovitis or oedema) or local
what are the forms of local soft tissues swellings
inflammatory (bursitis, rheumatoid nosules), infection (abscess), cystic lesions (ganglion, meniscal cyst, bakers cyst), benign neoplasms and malignant neoplasms
what should be included in a local soft tissue swelling history and examination
history:
painful? growing or fluctuated in size? solitary or multiple?
exam: site, size, definition, consistency (cystic, solid, soft, hard), surface (smooth irregular), mobility or fixity, temperature, pulsatility, transilluminable (fluid filled) pulsatility overlying skin changes local lymphadenopathy
what are features suggestive of a benign soft tissue tumour
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 of a possibly malignant soft tissue neoplasm
larger lesions (>5cm), rapid growth in size, a solid lesion, ill defined, irregular surface, associated lymphadenopathy, systemic upset (weight loss, apetite, fatigue)
what investigations might be needed for a swelling of unknown nature
MRI, ultrasound (to confirm a cystic lesion), biopsy
what is the commonest benign soft tissue tumours
lipoma
what is a lipoma
neoplastic proliferation of fat
what are malignant soft tissue tumours arising form connective tissues called
sacromas
e.g.
angiosarcoma- blood vessels
fibrosarcoma/ malignant fibrous histiocytoma- fibrous tissue
phabdomyosarcoma- skeletal muscle
synovial sarcoma- synovial lining of joints and tendons
where do you get ganglion cysts
around a synovial joint or synovial tendon sheath
what causes ganglion cyst
as a result of herniation or out pouching of a weak portion of the joint capsule or tendon sheath
weakness can be developmental (juvenile bakers cysts) or as a result of underlying joint damage/ arthritis with build up of pressure within the joint (adult bakers cyst, mucous cyst)
describe what ganglion cysts are like
well defined, may be quite firm and readily transilluminate
why would a ganglion cyst be excised
for local discomfort or cosmesis
what is a bursitis
an inflamed bursae
what is a bursae
a small fluid filled sac lined by synovium around a joint which prevents friction between tendons, bones, muscle and skin
what are 4 commonly inflamed bursae and why do they occur
(repeated pressure or trauma)
pre-patellar bursitis
olecranon bursitis
bunions
what are bunions
bursitis over the medial 1st metatarsal head in hallux valgus
what are two less common causes of bursitis
bacterial infections can cause a bursal abscess
gout
what happens over time with bursitis
the fluid component of the swelling may subside but a thickened bursal sac may be left
what is the treatment for sebaceous cysts and implantation dermoids
may require excision and or biopsy
why can an abscess occur on a limb
cellulitis, bursitis, penetrating wound or infected sebaceous cyst
what is the treatment for abcesses
antibiotics + incision and drainage
what is avascular necrosis
an ischaemic necrosis of bone predominantly
what sites are prone to AVN
femoral head, femoral condyles, head of the humerus, the capitellum, proximal pole of the scaphoid, proximal part of the talus
what can cause AVN
fracture, idiopathic,
alcoholism and corticosteroids can alter fat metabolism- fats gets into circulation- promote coagulation in prone areas/ increase fat content in the marrow (compresses venous outflow)
primary hyperlipidaemia
thrombophilia
sickle cell disease
antiphospholipis deficiency in SLE
the bends
what does AVN result in
necrosis of a segment of bone resulting in patchy sclerosis
subchondral collapse and irregularity of the articular surface
how can AVN affect osteoarthritic joints
causes collapse of articular surface and rapid deterioration
what is the treatment for AVN
if articular surface not collapsed- drilling under fluoroscopy to decompress bone, prevent further necrosis and promote healing
if collapsed- joint replacement (or fusion in wrist foot/ ankle)
what is the biochemistry of osteoporosis
quantitative defect resulting in reduce bone density and increase porosity = fragility
what is osteopenia
intermediate stage before osteoporosis
when does loss of bone density normally start to occur- why
age 30 due to gradual breakdown in osteoblastic activity
why do post menopausal females lose more bone mineral density
increase in osteoclastic bone reabsorption with the loss of protective effects of oestrogen (post menopausal osteoporosis)
what are the risk factors for post menopausal osteoporosis
early menopause, familial, environmental, smoking, alcohol abuse, lack of exercise, poor diet
what are the two type of osteoporosis
post menopausal and old age
what are the risk factors for old age osteoporosis
same as post menopausal with added:
chronic disease, inactivity, reduced sunlight exposure (vit D)
what usually happens in patients with post menopausal osteoporosis
colles fractures and vertebral insufficiency
what fractures are common in old age osteoporosis
femoral neck fractures and vertebral fractures
what other that the two types can osteoporosis arise from
coticosteroid use, alcohol abuse, malnutrition, chronic disease (CKD, malignancy, RA) and endocrine disorders (cushings, hyperthyroidism, hyperparathyroidism)
how is osteoporosis diagnosed
DEXA scanning- provides measure of bone mineral density
what are the treatments for osteoporosis
can only slow progression
- exercise
- good diet
- healthy levels of sunlight exposure
- calcium and vit D suppliments
- biophosphates (alendronate, risedronate, etidronate - reduce osteoclast resorption)
- desunomab (a monoclonal antibody which reduced osteoclast activity)
- strontium (increased osteoblast replication and reduces resorption)
what is the biochemistry of osteomalacia and rickets
a qualitative defect of bone with abnormal softening of the bone due to deficient mineralisation of osteoid (immature bone)
what is osteomalacia and rickets secondary to
inadequate amounts of calcium and phosphorus
what are the primary causes of osteomalacia and rickets
either insufficient calcium absorption from the intestine due to lack in diet or a deficiency/ resistance to the action of vit D
or a phosphate deficiency caused by renal losses
malnutrition, lack of sunlight (no vit D activation)
hypophosphataemia (refeeding syndrome, alcohol abuse, malabsorption, renal tube acidosis)
long term anticonvulsant use
chronic kidney disease
what are the symptoms of osteomalacia and rickets
bone pain, deformities, pathological fractures, symptoms of hypocalcaemia (paraesthesiae, muscle cramps, irritability, fatigue, seizures, brittle nails)
also pseudofractures (loosers zones)
what are the biochemical markers of osteomalacia
low calcium, low serum phosphate and high serum alkaline phosphatase
what is the treatment for osteomalcia and rickets
vit D therapy, calcium and phosphate supplements
what are there high levels of in hyperparathyroidism
parathyroid hormone and calcium
what can cause primary hyperparathyroidism
a benign adenoma, hyperplasia, malignant neoplasia (rarer)
what does an overproduction of PTH result in
hypercalcaemia- fatigue, depression, bone pain, myalgia, nausea, thirst, polyuria, renal stones, osteoporosis
what causes secondary hyperparathyroidism
physiological overproduction of PTH secondary to hypocalcaemia usually caused by vit D deficiency or CKD
what is tertiary hyperparathyroidism
when patients with chronic secondary hyperparathyroidism develop an adenoma which will continue to produce PTH
what is pagets disease
chronic disease that results in thickened brittle and miss-shapen bones
what are cement lines
lines surrounding osteon
what is freibergs disease
osteochondritis of the 2nd metatarsal head
what is kohlers disease
osteochondritis of the navicular bone
what is panners disease
osteochondritis of the capitellum of the elbow
what is kienbocks disease
osteochondritis of the lunate (within the wrist)
where do you get chondrosarcomas
axial skeleton
who gets chondrosarcomas
older patients
who gets osteosarcomas and where
younger patients
long bones, particularly at the metaphysis
what can osteosarcomas occur secondary to
pagets disease
what is pagets disease associated with
osteosarcoma in older patients
high cardiac output failure
