Fibrosarcoma can be primary or secondary due to Paget's disease, fibrous dysplasia, irradiated giant cell tumor, bone infarct or chronic osteomyelitis. Fibrosarcoma occurs both as an intramedullary and periosteal lesion. It presents in adults age 30 to 60 years old and affects men and women equally. The most common clinical presentation is that of a localized, painful mass. The radiologic picture of fibrosarcoma is that of an osteolytic lesion.
Periosteal reaction is seen with cortical destruction.
Extension into the soft tissue is common. MRI helps define intraosseus spread and soft tissue extension. Bone scan demonstrates increased uptake. The differential diagnosis includes leiomyosarcoma, metastatic carcinoma, melanoma, malignant fibrous histiocytoma and multiple myeloma. On gross examination the tumor is tan to grayish white with a rubbery consistency.