A bone sarcoma characterized by a herringbone or fascicular disposition of atypical, monomorphic fibroblasts and is always negative for any specific marker. [ url:https://www.orthobullets.com/pathology/8031/fibrosarcoma-of-bone url:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5732833/ url:https://link.springer.com/chapter/10.1007/978-1-4471-6578-1_29 ]