umls-concept:C0278595 | skos:definition | NCI: A malignant mesenchymal tumor composed of fibroblasts, and characterized by collagen production and a herringbone architectural pattern. It is more commonly seen in middle-aged and older adults. It usually affects the deep soft tissues of extremities, trunk, head and neck. Adult fibrosarcomas may recur and metastasise to the lungs and bones. | lld:umls |