Basic Science Flashcards
Benign bone tumour, bony outgrowth which cartilaginous cap
Osteochondroma
Where do osteochondromas typically occur?
Epiphysis of long bones, esp around the knee
Benign bone tumour, intramedullary metaphyseal cartilaginous tumour
Enchondroma
Symptoms of enchondroma
Asymptomatic
Appearance of bone in enchondroma
Usually lucent but may be patchy sclerotic
Where does enchondroma occur?
Tubular bones of hands and feet typically
How is an encondroma treated?
Scraped out
Benign bone tumour, solitary unicystic fluid filled neoplasm
Simple bone cyst
What causes a simple bone cyst?
Growth defect from physis
Where do simple bone cysts occur?
Metaphysis of long bones - usually proximal femur and humerus
Symptoms of simple bone cysts
Asymptomatic
Treatment of simple bone cyst
Curettage with bone graft +/- stabilisation
Benign bone tumour, locally aggressive, painful
Giant cell tumour
Where do giant cell tumours commonly occur?
Distal radius, knee, pevlix and spine
Which mutation is a/w a giant cell tumour?
Translocation between chromosome 1 and 2
How does a giant cell tumour appear on x-ray?
“soap bubble appearance”
Where may giant cell tumour metastasise to ?
Lung
How is a giant cell tumour treated?
Excision with phenol/bone cement/liquid nitrogen
Disease of the bone in adolescence, causes shepherd’s crook deformitiy
Fibrous dysplasia
What is the mutation in fibrous dysplasia?
Genetic mutation in G protein signalling
Where does fibrous dysplasia commonly affect?
Head and neck
What is polystotic fibrous dysplasia a/w?
Endocrine disorders
How is fibrous dysplasia treated?
Bisphosphonates for pain, stabilised fractures with internal fixation and cortical bone grafts
Why is intralesional excision not performed in fibrous dysplasia?
High recurrence rate
Benign bone tumour, small nidus of immature bone surrounded by a sclerotic halo, occurs in adolescence
Ostoid osteoma
Where is an osteoid osteoma common?
Proximal femur, diaphysis of long bones and vertebrae
Describe the pain in ostoid osteoma
Intense, constant, worse at night and relieved by NSAIDs
Describe the pain of an ostechondroma
Local pain
Describe the pain level of a giant cell tumour?
Painful
How is osteoid osteoma investigated?
X-Ray and CT
How is osteoid osteoma treated?
May spontaneously resolve
May need CT guided radiofrequency ablation
Which tumour is a/w hyperparathyroidism?
Brown tumour
Most common malignant bone tumour
Osteosarcoma
What mutation is a/w osteosarcoma?
Mutation in tumour suppressor retinoblastoma gene
Where are osteosarcomas commonly found?
Knee, proximal femur and pelvis
Where does an osterosarcoma metastasise to?
Blood, not lymph
Cartilage producing primary malignant bone tumour
Chondrosarcoma
What is the mean age to present with a chondrosarcoma
45
Where is a chondrosarcoma often found?
Pelvix or proximal femur
What is an issue in treating chondrosarcoma
Not radiosensitive or responsive to chemotherapy
Who gets Ewing’s sarcoma?
Teenagers
Where do Ewing’s sarcomas usually occur?
Long bones, femur
Malignant bone tumour, small round blue cell tumour
Ewing’s sarcoma
What mutation is a/w Ewing’s sarcoma?
t11;22 translocation on EWS gene on chromosome 22
How does Ewing’s sarcoma present?
Fever, raised inflammatory markers and warm swelling
When bone tumours are excised what margin around them is taken ?
3-4cm
Malignant cancer of round cells of the lymphocytic system and macrophages
Lymphoma
How is lymphoma treated?
Surgical resection
What is the mean survival with lymphoma?
<2 years
Malignant tumour from bone marrow
Myeloma
What is a solitary myeloma lesion called?
Plasmacytoma
What does a myeloma do?
Produce abnormal proteins which deposit in organ sites (amyloidosis)
Which age group gets myeloma?
45-65
How does myeloma present?
Weakness, back pain, bone pain, fatigue, weight loss and marrow suppression
How is myeloma diagnosed?
Plasma protein electrophoresis showing high paraprotein
Early morning urine for protein assay
How is myeloma treated?
Solitary - radiotherapy
Mulitple - chemotherapy
Which cancers commonly metastasise to bone?
Breast, prostate, lung, renal and thyroid
What are the mets like from breast cancer?
Blastic or lytics
Mean survival of breast cancer with bone mets?
24-26 months
Mean survival of lung cancer with bone mets
6 months
Mean survival of renal cell cancer with multiple mets?
12-18 months
How is fracture risk reduced in prostate cancer with bone mets?
Radiotherapy and hormone manipulation
What makes a soft tissue swelling more likely to be benign?
Small, fluctuation in size, cystic, well defined and soft
What makes a soft tissue swelling more likely to be malignant ?
Large (>5cm), rapidly growing, ill defined, solid
What is a lipoma?
Benign tumour in fat
What is a leiomyoma?
Benign tumour in smooth muscle
What is a chondroma?
Benign tumour in cartilage
What is a rhabdomyoma?
Benign tumour in skeletal muscle
What is a neuroma?
Benign tumour in nerve cells
Benign tumour in haemangioma?
Benign tumour in blood vessels
Small firm swelling on the flexor tendon sheath
Giant cell tumour of the tendon sheath
What is a complication of a giant cell tumour of the tendon sheath?
May erode bone
What does a giant cell tumour of the tendon sheath contain?
Multinucleated giant cells and haemosiderin
Which is excision not carried out?
High recurrence rate
What is pigmented villonodular synovitis?
Giant cell tumour in a joint
What is a sarcoma?
Malignant soft tissue tumour
What is an angiosarcoma?
Malignant tumour from blood vessels
What is cause of angiosarcoma?
Complication of previous radiotherapy
What is a liposarcoma?
Malignant tumour of fatty tissue
Where does a liposarcoma occur?
In deep fatty tissue
What is a rhabdomyosarcoma?
Malignant tumour of skeletal muscle
Where are synovial sarcomas common?
Around the knee
What are the two phases of a synovial sarcoma?
Sacromatous and epithelial
Swelling around a synovial joint or tendon sheath
Ganglion cyst
Why do ganglion cysts occur?
From weakened parts of the sheath or capsule, leading to out-pouching/herniation
How does a ganglion cyst appear?
Well defined, firm, transiluminate
Why is a ganglion cyst not really cystic?
Does not have an epithelial lining, only a fibrous wall
Swelling of the bursa following repeated pressure or trauma
Bursitis
Where is bursitis common?
Pre-patellar, olecranon, bunions
What can cause bursitis other than trauma?
Infection, gout
How is bursitis treated?
Inflammation spontaneously resolves, thickened bursal sac may remain and require excision
Painless, epidermal inclusion cysts
Sebaceous cysts
What lined an epidermal inclusion cyst?
Epithelium producing keratin
Swelling which is a collection of neutrophils, infective and cellular debris +/- infecting organisms
Abscess
How is an abscess treated?
Incision and drainage
What is a psuedotumour?
Swellings which mimic tumours but are actually reactive/inflammatory
Which process occurs in a pseudotumour?
Myositis ossificans
What is myositis ossificans
Unusual reaction to injury causing progressive ossification of a site
What is nodular fasciitis?
Rapid growth of lesion after trauma
What groups are at risk for AVN?
Alcohol and steroid abusers
What ratio does alcohol metabolism increase?
NADH : NAD
How does AVN appear?
Large wedge shaped area of discolouration, no osteocytes
What is creeping substitution?
Dead bone is slowly encircled by new, viable bone
What can cause AVN?
Primary hyperlipidaemia
Increased coagulation
Caisson’s disease
What is Caisson’s disease?
When nitrogen gas bubbles form in the body after too rapid a depressurisation in deep sea diving
How is AVN treated?
Early: drilling under fluoroscopy
Surface collapse: joint replacement
Fusion in foot/ankle
What does drilling under fluoroscopy do?
Compress the bone, prevent necrosis and encourage healing
What is osteochondritis?
Developmental derangement of normal bone growth with inflammation
What causes osetchondritis?
Increased physical activity and repetitive stress, FH important
What is the pathogenesis of osteochondritis?
Impact/traction injuries cause bleeding and oedema in bone
Capillary compression
Necrosis
There is fragmentation and separation of the bone
What is osteochondritis dissecans?
Osteochondritis which results in separation of the bone
Where is osteochondritis dissecans common?
Lateral part of medial condyle in the knee
Anteromedial talar dome
Superomedial femoral head
Humeral capitellum
What is Freiburg’s disease?
Osteochondritis in 2nd metatarsal head
What is Kohler’s disease?
Osteochondritis in navicular bone
What is Kienbock’s disease?
Osteochondritis in lunate or carpal bone
What is Scheuermann’s disease
Osteochondritis in the capitellum of the elbow
What is Osgood Schlatter disease?
Traction Osteochondritis at the tibial tubercle
What is Sever’s disease?
Osteochondritis at the calcaneus?
How it Osteochondritis dissecans treated?
Surgical realignment of the bone, OC dissecans pin or removal of unstable fragments
What is osteoporosis?
Reduced bone mineral density and increased pores causing increased fragility and fracture risk
What is the definition of osteoporosis?
Bone density 2.5 standard deviations below the mean of a young adult of the same race and gender
What is the definition of osteopenia?
Bone density 1-2.5 standard deviations below the mean of a young adult of the same race and gender
What is type 1 osteoporosis?
Post-menopausal
What are risk factors for type 1 osteoporosis?
Caucasian, smoking, alcohol, lack of exercise and poor diet
What is type 2 osteoporosis?
Osteoporosis of old age where bone density decreases by further than expected
What are the risk factors for type 2 osteoporosis?
Caucasian, smoking, alcohol, lack of exercise, poor diet, reduced sunlight/vit D and chronic disease
Which fractures are common with osteoporosis?
Femoral neck and vertebral
Which drugs can cause osteoporosis?
Corticosteroid
How is osteoporosis diagnosed?
DEXA scan
How is osteoporosis treated?
Vit D, calcium, bisphosphonates, desunomab, strontium
Which is intranasal calcitonin not used?
No benefit over other treatments and a risk of cancer
What are the risks of HRT and raloxifene?
HRT - breath and endometrial cancer as well as DVT
Raloxifene - DVT
What is osteomalacia?
Qualitative defect in bone resulting in abnormal softening due to deficient mineralisation of immature bone
What is Rickett’s?
Osteomalacia in kids
What are the two main causes of osteomalacia?
Insufficiet calcium absorption or vit D resistance
Phosphate deficiency due to renal losses
Which medications are a/w osteomalacia?
Anti-convulsants
What are the genetic causes of osteomalacia/Rickett’s?
X-Linked hypophosphataemia
Vit D resistant Rickett’s
How does osteomalacia present? (9)
Bone pain, deformity, fracture, paraesthesia, muscle cramp, irritability, seizures, brittle nails, faitgue
What are Looser’s zones?
Psuedofractures
Where are Looser’s zones found in osteomalacia?
Pubic rami, proximal femur, ulna and ribs
What are the biochemical findings of osteomalacia?
Low calcium, low serum phosphate, high serum alkaline phosphatase
How is osteomalacia treated?
Vit D therapy and supplementation
What is hyperparathyroidism?
Overactivity of the thyroid glands, producing lots of PTH
What can cause hyperparathyroidism?
Benign adenoma, hyperplasia or malignant neoplasia
How does hypercalcaemia present? (9)
Fatigue, depression, bone pain, myalgia, nausea, thirst, polyuria, renal stones, osteoporosis
What are the biochemical findings of hyperparathyroidism?
Serum PTH and calcium igh, phosphate normal or low
What is secondary hyperparathyroidism?
Overproduction of PTH in response to hypocalcaemia from vit D deficiency or CKD
What is tertiary hyperparathyroidism?
When adenomas develop in secondary HPT
How does hyperparathyroidism affect the bones?
Cause fragility fractures or lytic lesions
How is hyperparathyroidism treated?
Remove adenoma or give supplements - obvs based on underlying cause
How is very high serum calcium treated?
IV fluids, bisphosphonates and calcitonin
What is renal dystrophy?
Bone changes due to CKD
What affect does Paget’s disease have on the bones?
Chronic thickened, brittle and misshapen bones
How common is Paget’s disease
5% over 55
10% over 80
Which viruses is Paget’s disease a/w?
Paramyxoviruses, incl parainfluenza and mumps
What is the pathogenesis of Paget’s disease?
Exaggerated vit D response causes increased osteoclast activity
Osteoblasts try to keep up but make shit bone basically
How is Paget’s disease treated?
Bisphosphonates or calcitonin given if there is extensive lytic disease
Joint replacement
Stabilise fractures with intramedullary nails or plates
