Cortext - Pathology Flashcards
(25 cards)
Describe an osteochondroma?
Where do they commonly occur?
Risk of malignant transformation?
Bony outgrowth on external surface of bone covered in a cartilaginous cap
Around epiphysis of long bones, most common around the knee
1% risk of malignant transformation - any lesion growing in size or causing pain may require excisional biopsy
(multiple osteochondromas assoc w genetic conditions)
Describe an enchondroma?
What can happen to it to change its appearance?
Where do they occur?
Management?
Intramedullary, metaphyseal cartilaginous tumour
It can undergo mineralisation with a patchy sclerotic appearance
Small, tubular bones of hands and feet
Scraped out of bone if causing bother. Usually an incidental finding or cause of pathological fracture
Describe a simple (unicameral) bone cyst?
Cause?
Where are they found?
Management?
Solitary unicystic fluid-filled neoplasm
Probably a growth defect from physis (therefore metaphyseal in long bones)
Long bones - proximal humerus/femur, but also in talus/calcaneus
Usually incidental finding - if cause of pathological fracture then curettage and bone grafting
Describe an aneurysmal bone cyst? Cause? Where do they occur? Consequence? Management?
Cyst with many chambers, filled with blood or serum - the chambers can be seen on XR
Small AVM
Metaphysis of long bones, flat bones (ribs, skull), vertebral bodies
Can be locally aggressive causing cortical expansion and destruction, usually painful
Risk of pathological fracture - treat with curettage and grafting or bone cement
Describe a giant cell tumour? Where do they occur? Histology? XR appearance? Management? Malignant transformation?
Locally aggressive metaphyseal tumour which can extend to subchondral bone and epiphysis
Knee and distal radius but can affect other ling bones, pelvis or spine
Multi-nucleate giant cells, characterised by translocation between chromosome 1 and 2
Soap bubble appearance
Can cause pathological fractures, treat with phenol, bone cement and liquid nitrogen.
5% met risk to lungs
Describe fibrous dysplasia? Where does it affect? Cause? What bone problems can it lead to? What is seen on bone scans? Management?
Lesions of fibrous tissue and immature bone in adolescence due to a genetic mutation
Any bone, but most commonly head & neck
Abnormal G-protein signalling
Angular deformities, e.g. Shephard’s crook deformity of proximal femur - caused by defective bone mineralisation
Increased uptake during development, but lesions become inactive
Bisphosphonates reduce pain
ORIF for fractures
Describe an osteoid osteoma? Where do they occur? Clinical features? Ix? Management?
Small nidus of immature bone surrounded by intense sclerotic halo
Proximal femur, diaphysis of long bones and vertebrae - usually in adolescence
Intense, constant pain worse at night
(mediated by PG’s, NSAIDs relieve pain)
Can be seen on XR but bone scan/CT confirmatory
May resolve spontaneously, may need CT-guided radiofrequency ablation or en bloc excision
What is a Brodie’s abscess?
Subacute osteomyelitis - can present as lytic lesion of bone
What is a Browns tumour?
Hyperparathyroidism - can preset as lytic lesion of bone
When are bone tumours more common?
When are primary bone tumours more common?
In older age, but metastatic from e.g. prostate, breast, lung - or myeloma
Primary bone tumours are more common in younger patients
How can primary bone tumours sometimes show up early on?
ill-defined bony swelling on XR - this mandates further Ix
Unexplained MSK pain (commonly misdiagnosed as growth pains)
Systemic symptoms may then appear
How can malignant primary bone tumours show up XR?
Aggressive and destructive signs
- Cortical destruction
- Periosteal reaction (raised periosteum producing bone)
- New bone formation (sclerosis as well as lysis from destruction)
- Extension into surrounding soft tissues
What is the most common primary bone malignancy? Gene association? Age? Location? Mets? Management?
Osteosarcoma - bone-producing tumour
Mutation in tumour suppressor retinoblastoma
gene
Bones around knee (60%),, proximal femur, proximal humerus, pelvis
Adolescence/early adulthood
Haematological - most commonly to lung
Chemo
What is a chondrosarcoma? Age? Growth/mets? Location? Management?
Cartilage-producing primary bone tumour - less common and less aggressive than osteosarcoma
Older (mean 45 yo)
Can grow to be large, slow to metastasise
Pelvis/prox femur
Not radio/chemo-sensitive
What is a Ewing's Sarcoma? Age? Where? What is seen radiologically? Gene? How does it present?
More commonly occurring bone tumour of uncertain cell origin, similar to neuroectodermal tumours
(small round blue cell tumours)
Young
Long bones
Onion-skin pattern
t11;22 EWS gene
Fever, raised inflam markers, warm swelling - may be mis-diagnosed as osteomyelitis
Radio&chemo-sensitive
Staging of primary bone malignancies?
Bone scan and CT chest
MRI and CT can determine extent of local spread
Biopsy for histological diagnosis and grading
Surgery for primary bone malignancies?
Removal of tumour with 3-4cm margin and some muscle as well, reconstruct joints with special replacements
Adjuvant radio/chemo can improve survival
Is lymphoma a primary or metastatic bone cancer?
Can be either - primary usually in pelvis or femur
Met - splenomegaly/lymphadenopathy usually present
What is myeloma? Name of a single lesion? Type of amyloid? Presentation? Ix?
Malignant clonal proliferation of abnormal plasma cells, producing defective Ig
Myelocytoma (multiple = multiple myeloma)
Lytic lesions
AL amyloid (due to deposition of Ig light chain in organ tissues)
Age 45-65 - weakness, back pain, bone pain, fatigue, weight loss, anaemia, renal problems, recurrent infection, pathological #
Plasma protein electrophoresis (high level of paraprotein) OR urine collection for Bence Jones protein asssay
Skeletal survey of XR required as bone scan may not pick up due to no osteoblastic response to osteoclastic resorption
5 cancers which met to bone?
Breast Prostate Lung Renal cell Thyroid
What lesion does breast cancer cause in bone?
What type mets to bone?
Blastic (sclerotic) or lytic
Both lobular and ductal variants can
What lesion does prostate cancer cause in bone?
Do fractures heal?
What can help?
Sclerotic
Yes - due to osteoblastic activity
Radiotherapy and hormone therapy can reduce fracture risk
What lesion does lung cancer cause in bone?
Lytic
Mean survival 6 months once met to bone
What lesion does renal cell cancer cause in bone?
Prognosis?
Large and very vascular lytic (blow out) lesions
Can bleed lots on biopsy/surgery
With single bony met and primary tumour, surgery can be curative
Multiple bony mets 12-18 months