AP: Bone and Soft Tissue Tumours

Question 1

What is a classic example of a low-grade sarcoma?

Answer 1

Myxoid liposarcoma.

Question 2

What is a classic example of a high-grade sarcoma?

Answer 2

Synovial liposarcoma.

Question 3

What does an “intermediate malignancy” classification mean?

Answer 3

A high rate of local recurrence, but low rate of metastatic spread.

Question 4

What is the definition of soft tissue?

Answer 4

Tissues which are:

• non-epithelial
• non-reticuloendothelial
• non-CNS
• extra-skeletal

Question 5

What are some examples of soft tissue?

Answer 5

• Fibrous (connective) tissue
• Smooth muscle
• Skeletal muscle
• Fat
• Peripheral nerve
• Blood and lymphatics

Question 6

What is the relative frequency of benign : malignant lesions

Answer 6

At least 100:1

Question 7

What does “histogenic” classification ask?

Answer 7

What pattern of differentiation does the neoplasm demonstrate?

Question 8

What is the growth pattern of soft tissue neoplasm affected by?

Answer 8

• whether proliferative
• matrix-forming
• destructiveness
• response from surrounding tissue

Question 9

Describe the symptoms of SOFT TISSUE tumours

Answer 9

• Generally non-specific
• “Pressure” symptoms (pain, swelling from local impingement)
• Less commonly systemic effects

Question 10

How do BENIGN soft tissue tumours often (not always) present?

Answer 10

• <5cm
• Superficial to deep fascia
• Soft, moveable, non-tender
• Static/slow growth

Question 11

How do MALIGNANT soft tissue tumours often (not always) present?

Answer 11

• >5cm
• Deep to deep fascia
• Firm, fixed, tender
• Progressively increasing in size

Question 12

What are characteristics of INACTIVE BENIGN soft tissue tumours? Name 2 examples

Answer 12

• Asymptomatic
• intracompartmental
• encapsulated tumours.
• ganglion cyst, lipoma

Question 13

What is a ganglion cyst?

Answer 13

• Inactive, benign soft tissue tumour
• Cystic lesion developed by degeneration of joint capsule or tendon sheath, plus myxoid softening

Question 14

What is lipoma?

Answer 14

• Inactive, benign adipose tumour
• Single or multiple
• Superficial, well circumscribed

Question 15

What are ACTIVE BENIGN lesions? Name an example

Answer 15

• Grow steadily, expand by deforming surrounding tissue boundaries but remain encapsulated
• Giant Cell Tumour tendon sheath (localised tenosynovial giant cell tumour)

Question 16

What is an aggressive benign lesion?

Answer 16

Deep fibromatosis that is unusually symptomatic, rapidly growing and that infiltrates surrounding structures anatomical barriers

e.g. Nodular fasciitis

Question 17

What is Nodular Fasciitis?

(Hint: people often panic)

Answer 17

Rapidly enlarging pseudoneoplastic lesion common in young adults, often on upper limb.

Frequently misdiagnosed (clinically and pathologically)

Question 18

What are the characteristics of sarcomas? (malignant soft tissue tumours)

Answer 18

• Grow locally but can metastasise
• Compress adjacent tissue
• Form pseudocapsules (and extent as micoscropic tongues)

Question 19

What are the characteristics of low grade sarcomas?

Answer 19

• Gradual local expansion
• Low rate of metastatic spread

e.g. Myxoid Liposarcoma

Question 20

What are the characteristics of high grade sarcomas?

Answer 20

• Relatively rapid growth
• Extra-comparmental spread
• High rate of metastatic spread
• Often involve neurovascular bundles

(e.g. Synovial sarcoma)

Question 21

What are synovial sarcomas?

Answer 21

• 5-10% of all soft tissue sarcomas
• 80% occur around knee/ankle in young adults
• Males > females
• Grow close to joints, tendons
• Eventually develop recurrence and metastases

Question 22

Which factors affect sarcoma prognosis?

Answer 22

• Clinical stage (most important)
• Size
• Depth of tissue plane (superficial vs. deep)
• Histologic type
• Surgical margins

Question 23

What are the most common bone malignancies?

Answer 23

Bone metastases - caricnoma, melanoma, breast, prostate, lungs, thyroids, kidney

Question 24

What is the best way to detect bone metastases?

Answer 24

Radio isotope scanning (e.g. PET) - x-rays are not sensitive

Question 25

How do bone metastases present?

Answer 25

• Pain +/- swelling
• mass effect
• Pathological fracture
• hypercalcemia

Question 26

What is the most common primary malignant neoplasm of bone?

Answer 26

Plasma cell myeloma - characterized by secretion of single homogenous immunoglobulin product

Question 27

What is a plasmacytoma?

Answer 27

Rare, localized form of plasma cell neoplasm - restricted to 1 site only.

Question 28

What is osteochondroma?

Answer 28

Benign neoplasm of bone cartilage that presents as lumps on end of bones

Question 29

Describe osteogenic sarcoma

Answer 29

• Malignant tumour of bone
• Number 1 malignant primary tumour for bone
• More common in 10-20yo
• Occurs in distal femur and humerus

Question 30

Fill in the gaps: G_____ C____ T____ are _% of all bone tumours, and occur at the ______ end of a long bone in >__%

Answer 30

Giant Cell Tumours are 5% of all bone tumours, and occur at the articular end of a long bone in >75%

Question 31

What are the biopsy options for bone tumours?

Answer 31

• FNA
• Closed-core
• Open/excision

Question 32

What are inactive benign tumours? Examples

Answer 32

Features: completely encapsulated, stable or intermittently growing, usually asymptommatic, remain within compartment.

Examples: lipoma, ganglion cyst

Question 33

What is multiple myeloma?

Answer 33

Most common bone malignancy.

multifocal, in marrow, lytic, usually develop in later life, makes immunoglobulin which is excreted in urine

Symptoms:

• Compromised marrow = immunosuppression (frequent infections) & anaemia
• Pathological fractures
• hypercalcaemia
• Occasionally renal insufficiency and/or amyloidosis

Sites commonly involved = active marrow sites:

Pelvis, Clavicle, Femur, Ribs, Skull, Scapula, Vertebra