It's the soft-tissue sarcoma that specifically involves the spontaneous production of blood vessels to feed a tumor. When one miscreant cell deviates and divides to form a colony, a blood vessel develops to feed it. The vessel branches out and grows around the colony, creating a mass, anchoring like grappling hooks into a muscle. Hemangiopericytoma is closely related to and often mistaken for synovial sarcoma, another soft-tissue cancer. Tumors of the two varieties are so similar the differences are detectable only by a microscope.
Synovial sarcoma is a swifter killer.
Bill's odds were not bad at the start. His tumor was in a muscle wall, and when doctors removed it they cut through four ribs to make sure they got it all. Bill has a scar the size of a football. Doctors warned him that if even one cell escaped it could move to another part of his body and show up again. They told the Weddles that 30 percent of soft-tissue sarcoma patients survived.