Benign bone-cartilage tumours Flashcards
Define primary bone tumour?
Neoplasm/new growth that originates in bone
Are primary bone tumours common compared to secondary bone tumours?
No, primary bone tumours are uncommon
Do primary bone tumours tend to affect all age groups?
No, tend to affect certain age groups and locations
What are the 2 ways in which bone tumours are classified?
What normal cell type they originate from
What matrix they produce
In which age range are benign tumours most likely to occur?
First 3 decades of life (0-30)
Are benign or malignant tumours more common in general?
Benign tumours are more common than malignant tumours in general
Are older adults more likely to be affected by benign or malignant tumours?
Malignant tumours
What normal cell type does osteoma arise from?
Osteoblast
What is the maturity of the bone that is predominantly affected by osteoma?
Predominantly affects mature bone
Which body region is typically affected by osteoma, and give 3 specific areas within this region?
Cranio-facial region, especially jaw bones, temporal bones and paranasal sinuses
Which syndrome is osteoma a feature of?
Gardner syndrome
What are the 2 defining features of Gardner syndrome, and what kind of inheritance causes it?
Gardener syndrome is an autosomal dominant disorder that is characterised by multiple colorectal polyps (eg. inside large bowel) and tumours outside the colon
Are tumours outside the colon always benign, in patients with Gardner syndrome?
No, they are different kinds of benign and malignant tumours
Define polyp?
Projecting growth of tissue from a body surface, usually mucous membrane
Which normal cell type gives rise to enchondroma, and which part of the bone does this arise from?
hyaline cartilage
arises within medullary cavity
Do enchondromas commonly become malignant?
No, rarely become malignant
What condition increases the risk of enchondromas becoming malignant tumours?
Enchondromatosis (multiple enchondromas)
Which 2 conditions is enchondromatosis a characteristic feature of?
Ollier disease, Mafucci syndrome
Which normal cell type gives rise to juxtacortical/periosteal chondroma, and which part of the bone does this arise from?
Hyaline cartilage
Arises from cortex
Which part of the bone typically has tumour growth on the cortex, which have arisen from hyaline cartilage, and what is the classification of this tumour?
Juxtacortical/periosteal chondroma
Tumours arise on cortex on metaphysis of long tubular bones (eg. humerus, femur) or small tubular bones (eg. phalanges in hands and feet)
What are the 3 x-ray features of juxtacortical/periostral chondroma?
Circumscribed (confined to one area) lucency with central irregular calcifications
Sclerotic rim
Intact cortex
What is the characteristic shape of osteochondroma?
Exostosis (cartilage-capped tumour)
Which region of the bone does osteochondroma typically grow from, and what structure grows to connect to this area?
Metaphysis of long tubular bones (near growth plate)
Are bones affected by osteochondroma typically formed by endochondral or intramembranous ossification?
Endochondral ossification
Is osteochondroma more likely in men or women?
3x more likely in men
Is osteochondroma fast or slow growing?
Slow growing
Give 2 ways in which osteochondroma becomes painful?
Infringes on nerve
Bony stalk is fractured
In most patients, are osteochondromas solitary or multiple?
Solitary
What age range is typically affected by solitary osteochondromas?
Late adolescence/early adulthood
What condition is multiple osteochondromas a feature of?
multiple hereditary exostosis syndrome
Why is multiple hereditary exostosis syndrome commonly diagnosed in childhood?
Underlying bone bowed and shortened due to disrupted longitudinal growth from growth plate which has resulted in multiple osteochondromas
What is the difference between a sessile and pedunculated osteochondroma?
Osteochondromas with a visible stalk are called pedunculated.
Flatter ones with a broader base are called sessile
What direction does pedunculated osteochondroma typically point in relative to the joint?
Points away from the joint
Does the parent bone grow continuously with the pedunculated osteochondroma?
Yes, medullary cavity and cortex grow continuously
How thick is the cartilage cap of an osteochondroma?
2-3mm thick
What unusual radiological feature could be caused by a secondary pedunculated osteochondroma?
cartilage cap of lesion in excessively thick/irregular
How does the bony stalk of the pedunculated osteochondroma grow continuously with the parent bone?
Lesion undergoes endochondral ossification and trabecular bone fuses with normal trabecular bone below
Which bones are commonly affected by osteoid osteoma?
Osteoblast tumour that usually arise in cortex of long bones (mostly femur, tibia and lower extremities)
What is usually the diameter of osteoid osteoma?
Less than 2 cm
What is the usual age range of patients with osteoid osteoma, and are they more common in men or women?
Occurs in adults under 25 and is more common in men than women
What is the characteristic radiological feature of osteoid osteoma?
Thick rim of reactive cortical bone with radiolucent core
What is the characteristic macroscopic feature of osteoid osteoma?
Rounded, oval mass of red-brown tissue located on the cortex
What is the characteristic microscopic feature of osteoid osteoma?
Radiolucent nidus containing trabecular bone, cancer cells and vascular tissue surrounded by sclerotic bony shell
How intense is the pain caused by osteoid osteoma, and is it constant throughout the day?
Severe pain at night
What substance is released by osteoblasts that causes pain, in a patient with osteoid osteoma, and what drug class is prescribed for pain relief?
Pain caused by prostaglandins released by osteoblasts
Relieved by NSAIDs
What normal cell type does osteoblastoma originate from, and which body region is most commonly affected?
Osteoblast tumour
Predominantly affects posterior components of vertebrae, long bones of lower limbs
Do osteoblastomas usually become malignant?
Rarely become malignant
How can you differentiate between osteoid osteoma and osteoblastoma in terms of size?
Osteoid osteoma are less than 2cm in diameter
Osteoblastoma are more than 2cm in diameter
What kind of pain does a patient with osteoblastoma usually present with?
Vertebral pain with no marked bony reaction
Isn’t relieved by aspirin
Which 2 normal cell types give rise to Giant Cell Tumour of bone?
Multinucleated giant stromal cells (osteoclast precursors)
Osteoclasts
Which part of the bone is typically affected by Giant Cell Tumour of bone, and give 2 specific examples of long bones?
Epiphysis of long bones
Distal femur, proximal tibia (any long bones near joint)
Why does a patient with Giant Cell Tumour of bone present with arthritic symptoms?
Tumour is near joint
Does Giant Cell Tumour of bone affect all ages equally?
No, almost exclusively in young adults
Does Giant Cell Tumour of bone commonly metastasise to lungs, and is this always fatal?
4% metastasise to lungs, but these can spontaneously regress so are rarely fatal
What is the characteristic radiological feature of Giant Cell Tumour of bone, and why does this occur?
Expansive lytic lesion with ‘soap bubble’ appearance
Neoplastic osteoclast precursors express high RANKL levels, so osteoclast proliferation and bone resorption occurs at fast rate, produces lytic lesions
Explain how Giant Cell Tumour of bone is treated with cutterage?
Curette instrument is used to scrape the tumour out of the bone, then cavity is filled with a bone graft
40-60% treated tumours recur locally
