bone tumours

Question 1

Classify bone tumours

Answer 1

Benign
Malignant
-Primary
-Secondary

Question 2

What are the most common bone tumours in children, young adults and adults?

Answer 2

Most common bone tumours in children and young adults are primary benign bone tumours
Most common bone tumour in older adults are multiple myeloma and metastasis from other sites

Question 3

Describe mets to bone

Answer 3

Carcinomas much more common than sarcomas
–Carcinoma of the breast
–Prostatic carcinoma
–Bronchogenic carcinoma
–Renal cell carcinoma
Osteolytic
–Direct erosion of bone
–Stimulation of osteoclasts by cytokines (osteoclasts are macrophages) 
Osteosclerotic

Question 4

Complications of met tumours of bone

Answer 4

Pain
Pathologic fracture
Replacement of the bone marrow
Hypercalcaemia
Nerve and spinal compression

Question 5

Define myeloma

Answer 5

Primary malignant proliferation of plasma cells in the marrow
Solitary plasmacytoma or multiple myeloma

Question 6

Outline general features of primary bone tumour

Answer 6

Primary benign tumours are more common in children and young adult
Primary malignant tumours are more common in older individuals
Accurate diagnosis depend on clinical, radiologic and pathologic examination of the lesion
Many tumours characteristically involve certain part of bone

Question 7

What are the 3 types of primary bone tumours

Answer 7

Bone-producing tumours
Cartilage-producing tumours
Other types

Question 8

Outline bone forming tumours

Answer 8

Benign
–Osteoma
–Osteoid-osteoma
Locally aggressive
–Osteoblastoma
Malignant
–Osteosarcoma

Question 9

Define osteoma

site?

morphology?

Answer 9

Benign bone forming tumour
Often craniofacial in location
 Probably hamartomatous or reactive growth and not true neoplasm
Gardner syndrome - multiple osteomas

Question 10

Define osteoid osteoma
age of occurrence?
site?
morphology?

Answer 10

Benign bone forming tumour
Young age (second decade)
 Male: female = 3:1
Painful due to presence of high intra-lesional prostaglandin levels
Pain relived by aspirin

nidus producing blood vessels surrounded by bone which produces prostaglandin

Question 11

Features and tx of osteoid osteoma

Answer 11

Small size (<2cm)
Cortex of femur or tibia
Nidus consists of vascular spaces surrounded by sclerotic bone
Therapy - complete resection of nidus

Question 12

Define osteoblastoma
age of occurrence? 
site? 
morphology? 
tx?

Answer 12

Benign bone forming tumour
–Can be locally aggressive (local recurrence)
Young age
Most common location- vertebral column
> 2 cm
Minimal or no sclerotic reaction
Pain not relived by aspirin
Therapy- curettage/resection

Question 13

Define osteosarcoma
age of occurrence?
site?
morphology?

Answer 13

Malignant bone forming tumour
Bimodal age distribution
–Young - <20 years
–Second peak in elderly
End of long bones (classically around the knee)
Most arise in the metaphysis of a long bone

these tumors are composed of malignant mesenchymal cells that produce osteoid, often in an irregular, lace-like pattern

Question 14

Pathogenesis of osteosarcoma

Answer 14

Pathogenesis: 
Sporadic
Genetic (deletions and mutations in cell cycle regulators including Rb, p16 and p53)
Secondary osteosarcoma
–Radiation
–Paget’s disease

Question 15

Clinical features of osteosarcoma

Answer 15

Tenderness and/or pain of the affected region with or without a palpable mass
Fracture
Distant metastasis (lung

Question 16

Spread of osteosarcoma

Answer 16

Within the medullary cavity
Through the periosteum
Across epiphyseal plate
Haematogenous

Question 17

What are morphological features of osteosarcoma?

Answer 17

Codman’s triangle-lesion lifts periosteum

Sunray speculation-osteoid perpendicular to bone

Question 18

Tx, prognosis of osteosarcoma

Answer 18

Patients are usually treated with pre-operative chemotherapy and surgical resection
Poor prognosis- metastasis occur early in the course
The current disease-free-five-year survival rate is about 60%

Question 19

List cartilage producing tumours

Answer 19

Benign
–Osteochondroma
–Enchondroma
–Chondroblastoma
–Chondromyxoid fibroma
Malignant
–Chondrosarcoma

Question 20

Define osteochondroma
age of occurrence?
site?
morphology?

Answer 20

Age < 20 years
Multiple (osteochondromatosis-hereditary) or single (sporadic)
Mushroom-shaped bony projections from the lateral aspects of long bones
Arise from metaphysis
Chondrosarcomas can occasionally arise in osteochondromas; incidence is higher in osteochondromatosis

Question 21

Define enchondroma
age of occurrence?
site?
morphology?

Answer 21

Benign tumours of cartilage
-Any age (20 - 50 years)
Small bones of hands and feet
Arise from metaphysis
Single or multiple sites
-Ollier’s disease (usually one side of the body)
-Maffucci’s syndrome – (haemangiomas of soft tissue)
-Increased risk for chondrosarcoma
Well-circumscribed mature hyaline cartilage

Question 22

Define chondrosarcoma
age of occurrence?
site?
morphology?

Answer 22

Malignant tumour of cartilage
Second most common malignant tumour of bone
–Half as frequent as osteosarcoma
De novo or from a previous benign tumour
Middle age > 40
Axial skeleton (bones of pelvis and shoulder girdles, ribs and spine)
Morphologically, these tumours are composed of lobules of cartilage with chondrocytes in the lacunae and with focal ossification and calcification

Question 23

Spread, tx, prognosis of chondrosarcoma

Answer 23

These tumors can be quite aggressive and can erode through cortical bone to involve the soft tissues
Can metastasise to lungs, liver, kidney and brain
Chondrosarcomas are not sensitive to chemotherapeutic agents, and treatment is usually restricted to surgical resection
Poor prognosis (5 year survival rate 40%)

Question 24

Name a tumor that derives from EPIPHYSEAL of bone

Answer 24

osteoclastoma- giant cell tumor

Question 25

Define osteoclastoma
age?
site?
morphology?

Answer 25

Adults 20-55
Epiphyseal ends of long bones (knee)
Stromal cells and multinucleated osteoclast-like giant cells
 Locally aggressive tumour (high recurrence if curetted 50%)
4% are malignant and metastasize

Question 26

What is a tumour that arises from diaphysis of bone?

Answer 26

Ewing’s sarcoma

Question 27

Define Ewing’s sarcoma
age?
site?
morphology?

Answer 27

Origin- neuroectodermal
Age- children and young adults
Sites- medullary cavity in the diaphysis of long bones, pelvis and ribs
Chromosomal translocation t (11;22)
Small blue cells

Question 28

Dx, Tx, Px for Ewing’s sarcoma

Answer 28

X ray-Onion skin
Highly aggressive
Treatment-chemotherapy
Chemo + surgery has ↑ survival 5% » 75%
Prognosis- very poor
–<10% 5-year survival with surgery and radiotherapy
–40% with adjuvant chemotherapy