benign MSK tumours

Question 1

Classify overall all the different types of tumours affecting the skeletal muscle system

Answer 1

Primary - (benign, benign but locally aggressive, malignant) Secondary - metastatic lesions Myleoma

Question 2

What are the most common classification of bone tumours ?

Answer 2

Secondary they are more common than primary bone tumours ]

Question 3

What are the benign bone tumours ?

Answer 3

Osteochondroma Chondroma Osteoid osteoma Chondroblastoma.

Think ‘CO(O)C’

Question 4

Describe the epidemiology of osteochondromas (i.e. who is commonly affected)

Answer 4

Affects the young <20

Question 5

Describe the presentation of osteochondromas (will see them like this in an x-ray)

Answer 5

Arise on the external surface of bone, usually on the metaphysis near the epiphysis

Question 6

Describe the histopathology of osteochondromas

Answer 6

Cartilage capped bony projection containing a marrow cavity which is continuous with that of the underlying bone.

Question 7

Describe the epidemiology of chondromas (enchondroma)

Answer 7

Arises in the medullary cavity of bones esp of hands and feet Seen in young adults and > in men

Question 8

What are the different classifications of enchondroma and how do they relate to prognosis ?

Answer 8

You can have a single tumour known as enchondroma or you can have multiple which is called olliers disease and then if there is multiple tumours and presence of soft tissue haemangiomas then it is known as maffucis syndromeThis relates to prognosis as malignant change is very rare for a single enchondroma but muliple change is about 20% with maffucis syndrome it is even higher still

Question 9

Describe the clinical presentation of enchondromas (i.e. what you would see on radiology)

Answer 9

You would see lytic lesions with spotty calcification

Question 10

Describe the histopathology of enchondromas

Answer 10

Lobules of cartilage consisting of hyaline matrix containing uniform chondrocytes with darkly staining nuclei

Question 11

Describe the epidemiology of osteoid osteomas

Answer 11

Usually in children and young adults (10-30), > commonin men Commonly occurs in the shaft of long bones esp affecting the femur, tibia, hands/feet and axial skeleton Resolves without treatment

Question 12

What is the distinct clinical presentation of osteoid osteoma (not talking about on radiograph) mean like how it affects the patient

Answer 12

• Dull pain
• Worse at night
• Characteristically relieved by aspirin or NSAID’s

Question 13

What is the radiological appearance of osteoid osteoma

Answer 13

Radiolucent nidus (a site of origin)surroundedby a mass of sclerotic bone (thickening)Notice how it affects the shaft

Question 14

Describe the histopathology of osteoid osteoma

Answer 14

Nidus consists of osteoid (the unmineralized organic component of bone. Resembles bone)and woven bone surrounded by osteoblasts.

Question 15

Describe the epidemiology of chondroblastomas

Answer 15

Found at epiphysis of long bones Usually affects 10-20yr olds Can occasionally exhibit more aggressive course

Question 16

Describe the radiological appearance of osteoblastomas

Answer 16

Spherical and well-defined osteolytic foci, sometimes extending into the subarticular bone, joint space or metaphysisOsteolysisis an active resorption of bone matrix by osteoclasts and can be interpreted as the reverse of ossification.

Question 17

Describe the histopathology of chondroblastomas

Answer 17

Closely packed polygonal cells plus areas of immature chondroid (resembling cartilage)Distinct cytoplasmic borders with foci of “chicken-wire” calcification.

Question 18

What is the treatment for chondroblastomas ?

Answer 18

Biopsy and curettage plus adjuvant liquid nitrogen (think this is because they can be sometimes more aggressive compared to the other benign tumours)