Fibrosarcoma is a kind of malignant tumor originated from fibrous tissue, sometimes secondary to malignant osteitis, fibrous heteroproliferative disease, etc. After the lesion, it is a grayish-white fish-like sarcoma, and most of the sections are grayish-white in color. At present, the etiology of fibrosarcoma has not been clearly defined, and most of them are thought to be related to congenital factors, physical stimulation or radiation. Fibrosarcoma is currently a highly malignant tumor, usually presenting as a well-defined, round or oval shaped lesion with grayish-white fish-like sarcomatoid tissue. If differentiation improves, the section may appear grayish-white. The main symptoms of fibrosarcoma are progressive pain, swelling, and pathological fracture if it extends to soft tissues. If it is determined to be fibrosarcoma through pathological examination or immunohistochemical examination, timely treatment should be carried out to prevent the sarcoma lesion from invading neighboring tissues and aggravating the condition.