The spread of any tumor, including sarcomas should be thought of in terms of:
1. Local spread:
- Invasion of surrounding tissues
2. Lymphatic spread:
- To adjacent draining lymph nodes
3. Blood "stream" spread:
- To distant sites such as lung and bone
In terms of spread, sarcomas commonly travel via the blood stream to tissues such as bone and lung.
It is unusual for sarcomas to spread to adjacent lymph nodes, but this can occur and is commoner in some types of sarcoma.
Lymph node spread can occur in:
- Rhabdomyosarcoma (especially alveolar subtype)
- Epithelioid sarcoma
- Clear cell sarcoma
- Malignant fibrous histiocytoma (pleomorphic sarcoma)
- Ewing sarcoma (extra-osseous)
- Synovial sarcoma
- Alveolar soft part sarcoma
Sometimes there can be other routes of spread:
- Base of skull and spinal sarcomas can spread via the CSF pathways.
- Adjacent tissues and muscle compartments can be contaminated by poorly planned excisional biopsies.