c) Vascular Sarcoma
Vascular tumours are relatively common but are usually benign; haemangioma is a common skin lump that requires no treatment or local excision only. Haemangiomas can occur in other body sites as well, although rarely (eg. intramuscular, synovial).
Of concern to the radiation oncologist are the malignant vascular sarcomas - angiosarcoma, epithilioid haemangioendothelioma, and Kaposi's sarcoma.