Malignant MSK tumours Flashcards
What is a malignant tumour of fat known as?
Liposarcoma
What is a malignant tumour of blood vessels known as?
Angiosarcoma
What is a malignant tumour of smooth muscle known as?
Leiomyosarcoma
What is a malignant tumour of skeletal or cardiac muscle known as?
Rhabdomyosarcoma
What is a malignant tumour of cartilage known as?
Chondrosarcoma
What is a malignant tumour of bone known as?
Osteosarcoma
Who is most at risk of developing liposarcoma?
Ages 50 - 60
What are the 3 histological sub-types of liposarcoma?
- Well-differentiated
- Myxoid
- Pleomorphic
Where do liposarcomas most commonly form?
Deep soft tissue of extremities or retroperitoneum
Who is most at risk of developing leiomyosarcoma?
Females
Where do leiomyosarcomas most commonly form?
Deep soft tissues of the extremities and retroperitoneum
Great vessels (e.g. IVC)
What are some complications of leiomyosarcoma?
These can be lethal due to local invasion and metastasis, most commonly via haematogenous spread to the lungs
What are the 3 categories of rhabdomyosarcoma?
- Embryonal
- Alveolar
- Pleomorphic
How should rhabdomyomas be treated?
They are aggressive tumours so require surgery and adjuvant therapy
When do embryonal rhabdomyosarcomas occur?
During early childhood
What are some structures affected by embryonal rhabdomyosarcoma?
- Genital tract (Botyroides)
- GU tract
- Head and Neck (Periorbital)
- Common bile duct
What are botyroides?
Embryonic rhabdomyosarcomas of the genital tract
Describe the histology of boytryoides?
Botyroides forms have cambium layers, in which there is condensation of the tumour cells below the mucosal surface
Who is most commonly affected by alveolar rhabdomyosarcomas?
Young adults
What are the most common sites affected by alveolar rhabdomyosarcoma?
Head and neck
What gene mutations are associated with alveolar rhabdomyosarcoma?
FOXO1 (PAX 3 or 7 mutations)
Who is most commonly affected by pleomorphic rhabdomyosarcoma?
Older age groups
What will immunohistochemistry show in pleomorphic rhabdomyosarcoma?
MYOD1
Myogenin
What are chondrosarcomas?
These are a malignant tumour that produces cartilage
Who is most commonly affected by chondrosarcoma?
These are most common in adults over 40, except clear cell and mesenchymal, which affect younger patients
Where do chondrosarcomas most commonly affect?
Axial skeleton (Most commonly head and neck)
Where do clear cell chondrosarcomas most commonly affect?
Epiphysis of long tubular bones
What are the histological subtypes of chondrosarcoma?
- Conventional: Intramedullary (Central) or juxtacortical (peripheral)
- Clear cell
- Mesenchymal
- Dedifferentiated
How are chondrosarcomas graded?
They are graded from 1 to 3, depending on cellularity, cytological atypia and mitotic activity
Describe the histology of conventional chondrosarcomas?
They are bulky tumours forming nodules of grey cartilaginous tissue with gelatinous matrix
They locally invade bone, muscle and fat
Describe the histology of de-differentiated chondrosarcomas
These are low grade chondrosarcomas with a separate high grade component that does not produce cartilage
Describe the histology of clear cell chondrosarcomas
Histologically, malignant chondrocytes have abundant clear cytoplasm, associated osteoclastic cells and reactive bone that can suggest osteosarcoma
Describe the histology of mesenchymal chondrosarcomas
Histologically, these show sheets of well differentiated hyaline appearing cartilage with surrounding small round cells
What is the most common method and site of metastasis in chondrosarcoma?
Haematogeous spread to the lungs
What are osteosarcomas?
These are malignant lesions that produce bone, most commonly found in the primary sarcoma of the bone
Who is most at risk of developing osteosarcomas?
Paediatric group
Elderly (Associated with Paget’s disease)
Where do osteosarcomas usually affect?
Long bones
How are osteosarcomas diagnosed?
They are diagnosed using radiography, showing signs such as Codman’s triangle, in which the reactive bone lifts the periosteum up, forming a triangle
Any malignant tumour that produces osteoid is an osteosarcoma until proven otherwise
How may osteosarcomas metastasise?
Metastatic spread is usually haematogenous but can be lymphatic
10-20% of patients have pulmonary metastases at diagnosis
What are Ewing’s sarcomas?
They are destructive, rapidly growing and highly malignant tumours of unknown origin that can affect any soft tissue or bony location
Who is most at risk of Ewing’s sarcoma?
Children and adolescents (Ages 10-20)
What are the supposed cells of origin in Ewing’s sarcoma?
Primitive mesenchymal cells or neuroectodermal cells
Describe the histology of Ewing’s sarcoma
They form small round blue cell tumours
How will Ewing’s sarcoma present?
This will often present with hot, swollen, tender joints or limbs with raised inflammatory markers
They can often mimic infection
What are sarcomatoid carcinomas?
Sarcomatoid carcinomas are thought to be caused by pluripotential stem cells that become malignant
What are fibrosarcomas?
These are fibrous malignant primary bone tumours which tend to occur in abnormal bone e.g. bone infarct, post radiation
Fibrosarcoma tends to affect adolescents/YAs
What are the most common origins of bony metastases?
Lungs
Kidneys
Breasts
Prostate
What is meant by osteolytic?
Tumours that resorb bone
What is meant by osteosclerotic?
Tumours that cause fibrosis of bone
How will osteolytic bone tumours present on X-ray?
Radiolucency
How will osteosclerotic bone tumours present on X-ray
Radio opaque
