Histo: Neoplastic Bone Disease

Question 1

Which part of the body is most commonly affected by osteosarcoma?

Answer 1

Knee 60%

Question 2

Outline some presenting features of neoplastic bone disease.

Answer 2

• Pain
• Swelling
• Deformity
• Fracture

Question 3

What type of biopsy is often used for diagnosing neoplastic bone disease?

Answer 3

Needle biopsy using a Jamshidi needle under CT or US guidance

Question 4

List some tumour-like conditions of the bone.

Answer 4

• Fibrous dysplasia
• Simple bone cyst

Question 5

What is fibrous dysplasia?

Answer 5

• Condition in which fibrous tissue develops in place of normal bone tissue
• Can occur in any bone but ribs and proximal femur is most common
• Tends to affect patients < 30 years
• Causes soap bubble osteolysis on X-ray

Question 6

Which eponymous syndrome is characterised by polyostotic fibrous dysplasia?

Answer 6

McCune Albright Syndrome - polyostotic fibrous dysplasia + endocrine problems + rough border café-au-lait spots

Question 7

Describe the histological appearance of fibrous dysplasia.

Answer 7

The marrow is replaced by fibrous stroma with rounded trabecular bone (‘Chinese letters’)

Question 8

Describe the X-ray appearance of fibrous dysplasia of the femoral head.

Answer 8

Shepherd’s crook + soap bubble osteolysis

Question 9

List three types of cartilaginous benign bone tumour.

Answer 9

• Osteochondroma
• Enchondroma
• Chondroblastoma

Question 10

List three types of bone-forming benign bone tumour.

Answer 10

• Osteoid osteoma
• Osteoma
• Osteoblastoma

Question 11

What are osteochondromas and which bones tend to be affected? Histological and X-ray findings?

Answer 11

• A benign overgrowth of cartilage and bone that tends to happen at the ends of long bones
• They mimic normal tubular bone as they have a cartilaginous surface overlying normal trabecular bone

Mushroom bony outgrowth on histology

bony protuberance from bone on X-ray

Question 12

What is an enchondroma and which bones tend to be affected?
X-ray finding?

Answer 12

• A cartilaginous proliferation within the bone
• Most tend to be found in the hands and can cause pathological fractures
• X-ray may show popcorn calcification

Ends - end of arms - hands

Question 13

Xray findings of benign vs malignant bone disease?

Answer 13

Benign - regular bone formation, intraossesous and regular calcification

Malignant - varied bone formation, extra osseous and irregular calcification

Question 14

What are giant cell tumours? Where do they tend to be found and what is their histological appearance?

Answer 14

• Benign/borderline malignant tumour of the bone characterised by the presence of lots of osteoclasts (giant cells)
• They tend to be found at the ends of long bones
• It has a lytic appearance on X-ray
• Histology shows many osteoclasts on a background of spindle/ovoid cells and soap bubble

Question 15

What is the most common and second most common type of malignant bone tumour?

Answer 15

Metastases and then osteosarcoma

Question 16

Which cancers in adults tend to spread to the bone?

Answer 16

• Breast
• Prostate
• Lung
• Kidney
• Thyroid

Question 17

Which cancers in children tend to spread to the bone?

Answer 17

• Neuroblastoma
• Wilm’s tumour
• Osteosarcoma
• Ewing’s sarcoma
• Rhabdomyosarcoma

Question 18

List three types of malignant bone tumour.

Answer 18

• Osteosarcoma
• Chondrosarcoma
• Ewing’s sarcoma/PNET

Question 19

What is an osteosarcoma?

Answer 19

• Malignant bone-forming tumour of the bone that mainly occurs at the ends of long bones
• Tends to occur at age 10-30 years

Question 20

Describe the X-ray appearance of osteosarcoma.

Answer 20

• Usually metaphyseal
• Lytic
• Elevated periosteum (Codman’s triangle)
• sunburst appearance

Question 21

Describe the histological appearance of osteosarcoma + blood test?

Answer 21

• There are lots of malignant mesenchymal cells with or without bone and cartilage formation

NOTE: this can be stained for using ALP

High ALP

Question 22

What is a chondrosarcoma?

Answer 22

• Malignant cartilage producing tumour
• Tends to occur in patients aged > 40 years

Question 23

Describe the X-ray appearance of chondroscarcoma.

Answer 23

Lytic with fluffy calcification

Question 24

What is an Ewing’s sarcoma?

Answer 24

• Highly malignant small round cell tumour
• Occurs in people < 20 years old

Question 25

Describe the X-ray appearance of Ewing’s sarcoma.

Answer 25

• Onion skinning of the periosteum
• Lytic with or without sclerosis

Question 26

Describe the histological appearance of Ewing’s sarcoma.

Answer 26

Sheets of small round cells

Question 27

Which genetic abnormality is associated with Ewing’s sarcoma?

Answer 27

Chromosomal translocation 11:22 (EWSR1/FLI1) (q24:q12)

Question 28

Define soft tissue tumour.

Answer 28

Mesenchymal proliferations which occur in the extra-skeletal, non-epithelial tissues of the body - excluding meninges and lymphoreticular system

Question 29

List some special diagnostic techniques used to diagnose soft tissue tumours.

Answer 29

• Immunohistochemistry
• Electron microscopy
• Cytogenetic
• FISH
• RT-PCR

Question 30

List some bad prognostic factors for soft tissue tumours.

Answer 30

• Size
• Depth
• Grade
• Vascular invasion
• Ploidy

Question 31

Most common benign bone tumour?

Answer 31

Osteochondroma

Question 32

What bones does ewing’s sarcoma usually affect and what age group?

Answer 32

Long bones and pelvis, <20y

Question 33

What age group for each of these:
Osteosarcoma
Ewing’s sarcoma
Chondrosarcoma

Answer 33

Osteosarcoma - children
Ewing’s sarcoma - <20
Chondrosarcoma - >40

Question 34

Which bone tumour has the worst prognosis?

Answer 34

Ewing’s sarcoma as it is highly malignant