[Aggressive fibrous histiocytoma of bone--report of two cases]

Three osseous tumors multicentrically arising in the radius, ulna, and metacarpal bones of a 10-year-old girl and another in the femur of a 75-year-old man are reported. These lesions were designated as aggressive fibrous histiocytoma because of the benign cytological appearance with aggressive roentgenographic findings. These tumors were composed mainly of spindle cells tightly packed in a storiform pattern. Clear histiocytes and multinuclear giant tumor cells were occasionally seen. Variable amounts of collagen fiber were found. Both patients have been followed for 32 and 21 months respectively without evidence of local recurrence or distant metastasis.