Benign bone lesions Flashcards by Cathy Wang

What is osteochondroma

Benign bony lesion that arises from perichondral ring

How well did you know this?

Not at all

Perfectly

What is the perichondral ring

Circumferential fibrous layer that secures the epiphysis and metaphysis together

How well did you know this?

Not at all

Perfectly

Where is osteochondroma found

At the end of the bone near growth plate

How well did you know this?

Not at all

Perfectly

Osteochondroma is commonly seen in which age group

Adolescents and young adults 10-20 years old

How well did you know this?

Not at all

Perfectly

Osteochondroma can be solitary or multiple. Multiple osteochondroma can be due to

autosomal dominant disorder: Multiple hereditary Exostosis

How well did you know this?

Not at all

Perfectly

Describe the structure of osteochondroma

Bony outgrowth near the end of the bone with a cartilaginous cap

How well did you know this?

Not at all

Perfectly

Clinical presentation of osteochondroma

Painless
Hard lump
May have pain / numbness during activities

How well did you know this?

Not at all

Perfectly

Osteochondroma commonly occur at

Distal femur
Proximal tibia

How well did you know this?

Not at all

Perfectly

Investigations for osteochondroma

Xray or MRI

How well did you know this?

Not at all

Perfectly

Management for osteochondroma

Close observation
may require removal if it grows or causes pain

How well did you know this?

Not at all

Perfectly

Risk of osteochondroma developing into malignancy is

Small <1%
but higher in multiple hereditary exostosis due to more lesions

How well did you know this?

Not at all

Perfectly

What is enchondroma

Intramedullary and metaphyseal cartilaginous tumour

How well did you know this?

Not at all

Perfectly

Cause of enchondroma

Failure of endochondral ossification

How well did you know this?

Not at all

Perfectly

What is endochondral ossification

Process of bone formation where cartilage is gradually replaced by bone

How well did you know this?

Not at all

Perfectly

Which bones are not formed by endochondral ossification

Skull
Mandible
Clavicles

How well did you know this?

Not at all

Perfectly

Enchondroma usually presents in which age group

20-50

How well did you know this?

Not at all

Perfectly

Where does enchondroma occur

Intramedullary, at metaphysis

How well did you know this?

Not at all

Perfectly

Which bones are commonly affected by enchondroma

Femur
Humerus
Tibia
Small bones of hands and feet

How well did you know this?

Not at all

Perfectly

Enchondroma can lead to

Pathological fractures because they can weaken the bone
but usually asymptomatic

How well did you know this?

Not at all

Perfectly

Investigations for enchondroma

Xray

How well did you know this?

Not at all

Perfectly

Presentation of enchondroma on Xray

Lucent
Patchy sclerotic appearance

How well did you know this?

Not at all

Perfectly

Management of enchondroma

curettage then fill with bone graft if there is risk of pathological fracture / fracture already occurred

How well did you know this?

Not at all

Perfectly

What is a bone cyst

Benign fluid filled cyst in bone

How well did you know this?

Not at all

Perfectly

Where is bone cyst usually located at

Metaphysis

How well did you know this?

Not at all

Perfectly

Which bones are usually affected by bone cysts

Proximal humerus Femur Talus calcaneus

What can bone cysts lead to

Pathological fracture due to weakening of the bone But usually asymptomatic

Investigations for bone cysts

Xray

Management of bone cysts

Curettage then fill with bone graft

What is aneurysmal bone cyst

Lesion made of many chambers filled with blood or serum in bone

Cause of aneurysmal bone cyst

Small arteriovenous malformation

Where does aneurysmal bone cyst usually occur

metaphyses

What type of bones do aneurysmal bone cyst affect

Long bones Flat bones - skull / clavicle/ scapula / mandible ..etc Vertebral bodies

Symptoms of aneurysmal bone cyst

Painful mass Swelling pathological fracture

Investigations for aneurysmal bone cyst

Xray

Management of aneurysmal bone cyst

Curettage then bone graft

What is giant cell tumour of bone

Benign lesion arising from the giant cells of the bone marrow

Where does giant cell tumour of bone usually occur

Metaphyseal region Involves epiphysis Can extend to adjacent subchondral bone in joint

What is subchondral bone

The bone tissue lying beneath cartilage in a joint

Clinical presentation of giant cell tumour of the bone

Painful mass Swelling Pathological fracture

Which bones are commonly affected by giant cell tumour of the bone

Knee Distal radius Pelvis Spine other long bones

Xray presentation of giant cell tumour of the bone

Soap bubble appearance

Histology of giant cell tumour of the bone will show

Multi-nucleated giant cells

Management of giant cell tumour of the bone

Phenol / Bone cement / Liquid nitrogen Joint replacement if damage to cortical layer of bone

Giant cell tumour of the bone can metastasise to

Lungs as benign pulmonary giant cell tumour

What is fibrous dysplasia

Benign, developmental disorder of bone that causes normal skeletal tissue to be replaced by fibrous tissue

Cause of fibrous dysplasia

Genetic mutation

Fibrous dysplasia usually occurs in which age group

Adolescents

Clinical presentation of fibrous dysplasia

Deformities Bone pain Pathological fractures

What happens to the bone structure in fibrous dysplasia

Affected bone is wider with thinner cortical layer

Investigations for fibrous dysplasia

Bone scan Xray

Bone scan result for fibrous dysplasia

Increase in uptake of radioactive substances during development of the lesion then becomes inactive

Xray presentation of fibrous dysplasia

Shepherd's crook

Management of fibrous dysplasia

Bisphosphonates Internal fixation Cortical bone grafts

What is osteoid osteoma

Benign bone-forming tumors that typically occur in children

Osteoid osteoma usually affects which bones

Proximal femur Diaphysis of long bones Diaphysis of vertebrae

Clinical presentation of osteoid osteoma

Constant severe pain Pain worse at night Pain relieved by NSAID

Investigations for osteoid osteoma

Bone scan - increased uptake CT

Presentation of osteoid osteoma on CT

Lucent nidus surrounded by sclerotic bone

What is nidus

Center of an osteoid osteoma, consists of growing tumour cells, blood vessels and cells that form bone

Management of osteoid osteoma

May resolve spontaneously If not -> CT guided radio frequency ablation

What are lipomas

Benign soft tissue lesion due to neoplastic proliferation of fat

Characteristics of soft tissue neoplasm like lipomas

Smaller Fluctuates in size Well defined lesions Fluid filled lesions No overlying skin changes Fatty lesions

Risk factors of bone cancer

Young Previous radiotherapy Paget's / Multiple enchondromas / Fibrous dysplasia Li Fraumeni syndrome Familial retinoblastoma

Malignant bone tumours are often found at early / late stages

Late

What is Li Fraumeni syndrome

Inherited disorder predisposing people to malignancies due to mutation in p53

Li Fraumeni syndrome is inherited in which pattern

Autosomal dominant

Types of malignant bone tumours

Multiple myeloma Osteosarcoma Chondrosarcoma Ewing's sarcoma Fibrosarcoma

What is multiple myeloma

Malignancy from plasma cells in the bone marrow

4 characteristics of Multiple myeloma

Hypercalcaemia Anaemia Renal impairment Bone pain

Multiple myeloma usually affects which age group

Elderly

Most common type of sarcoma

Osteosarcoma

What is osteosarcoma

Malignant tumour that produces bone

How does osteosarcoma usually spread

Haematogenous

Osteosarcoma that occurs in elderly is associated with

Paget's disease

Which bones are commonly affected by osteosarcoma

Distal femur Proximal tibia Proximal humerus Pelvis

What is chondrosarcoma

Malignany of chondrocytes causing production of cartilage

How often does chondrosarcoma arise from benign lesions such as enchondroma and osteochondroma

Rare, most arise de novo

Which bones are often affected by chondrosarcoma

Pelvis Proximal femur

How aggressive is chondrosarcoma

Less aggressive than osteosarcoma Slow to metastasise

Chondrosarcoma tends ot affect which age group

45 years old; older age group

What is fibrosarcoma

Fibrous malignant tumours

Fibrosarcoma tend to affect which bones

Abnormal bones such as bone infarcts / post radiation bones

Which age group is usually affected by fibrosarcoma

Young adults / adolescents

What is Ewing's sarcoma

Tumour of the endothelial cells of the bone marrow

2nd most common bone tumour in children is

Ewing's sarcoma

Ewing's sarcoma tend to affect which age group

10-20

Presentation of Ewing's sarcoma

Hot, swollen, tender joint

which bones are often affected by Ewing's sarcoma

Distal femur Proximal tibia

Investigations for bony tumours

Xray Biopsy Staging using bone scan, CT, MRI

What would the xray results be for malignant bone tumours

Aggressive Cortical layer damaged Sclerosis Loss of bone - lysis

Management of malignant bone tumours

Surgery Adjuvant chemotherapy /radiotherapy Neo-adjuvant chemotherapy

Which type of malignant bone lesion does not respond to chemotherapy

Chondrosarcoma

What are the cancers that commonly metastasise to the bone

Breast Prostate Lungs Renal cell carcinoma Thyroid cancer

Prostate cancer often gives which type of metastases

Sclerotic metastases

Lung cancer often gives which type of metastases

Lytic metastases

Renal cell carcinoma often gives which type of metastases

Large, very vascular lytic metastases These can bleed a lot during biopsy or surgery