Sarcomas

Question 1

General Info

Answer 1

Malignant tumours of mesenchymal origin
May be either bone or soft tissue in origin.
Certain features of a mass or swelling should raise suspicion for a sarcoma these include:
- Large >5cm soft tissue mass
- Deep tissue location or intra muscular location
- Rapid growth
- Painful lump

Question 2

Ewings sarcoma

Answer 2

Commoner in males
Incidence of 0.3 / 1, 000, 000
Onset typically between 10 and 20 years of age
Location by femoral diaphysis is commonest site
Histologically it is a small round tumour
Blood borne metastasis is common and chemotherapy is often combined with surgery

Question 3

Osteosarcoma

Answer 3

Mesenchymal cells with osteoblastic differentiation
20% of all primary bone tumours
Incidence of 5 per 1,000,000
Peak age 15-30, commoner in males
Limb preserving surgery may be possible and many patients will receive chemotherapy

Question 4

Liposarcoma

Answer 4

Malignancy of adipocytes
Rare, approximately 2.5 per 1,000,000. They are the most common soft tissue sarcoma
Typically located in deep locations such as retroperitoneum
Affect older age group usually >40 years of age
May be well differentiated and thus slow growing although may undergo de-differentiation and disease progression
Many tumours will have a pseudocapsule that can misleadingly allow surgeons to feel that they can ‘shell out’ these lesions. In reality, tumour may invade at the edge of the pseudocapsule and result in local recurrence if this strategy is adopted
Usually resistant to radiotherapy, although this is often used in a palliative setting

Question 5

Malignant Fibrous Histiocytoma

Answer 5

Tumour with large number of histiocytes
Also described as undifferentiated pleomorphic sarcoma NOS (i.e. Cell of origin is not known)
Four major subtypes are recognised: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell and inflammatory
Treatment is usually with surgical resection and adjuvant radiotherapy as this reduces the likelihood of local recurrence

Question 6

Bone sarcomas

Answer 6

Osteosarcoma
Ewings sarcoma (although non bony sites recognised)
Chondrosarcoma - originate from Chondrocytes

Question 7

Soft tissue sarcomas

Answer 7

Liposarcoma-adipocytes
Rhabdomyosarcoma-striated muscle
Leiomyosarcoma-smooth muscle
Synovial sarcomas- close to joints (cell of origin not known but not synovium)