What is the definition or description of: sarcoma?

Kind of cancer: By definition, it is malignant (i.e., being locally invasive and at least theoreticlally capable of metastasizing), and arises from / mimics muscle or connective tissue elements that are not marrow or immune / white cells. The sarcomas are a tremendously varied and troublesome family of tumors, though thankfully less common than carcinomas and the leukemia / lymphoma / myeloma family.

Cancer of bone/soft: Sarcomas are relatively rare bone and soft tissue cancers. They are a heterogeneous group of cancers that are grouped together because they generall arise from bone and soft tissues. The most common bone sarcoma is osteosarcoma followed by ewing sarcoma that can arise from bone and soft tissue followed by chondrosarcoma. In soft tissues, there are many many different types.