Source:http://linkedlifedata.com/resource/umls/id/C0410005
NCI: A rapid growing, non-encapsulated benign neoplasm that arises from the soft tissues. It is characterized by the presence of non-hyperchromatic spindle-shaped fibroblasts, multinucleated osteoclast-like giant cells, chronic inflammatory infiltrate, red blood cell extravasation, and high mitotic activity, in a storiform growth pattern.