Prognostic factors of malignant fibrous histiocytoma of bone. A clinical and histopathologic analysis of 34 cases.

BACKGROUND

Malignant fibrous histiocytoma (MFH) of bone is a rare bone tumor, and its prognosis has been controversial.

METHODS

Thirty-four patients with MFH of bone were examined clinicopathologically for prognostic factors.

RESULTS

The most common skeletal site of the tumor was the femur (15 cases), followed by the pelvic bones (6 cases), tibia (5 cases), and fibula (5 cases). Of 29 patients available for follow-up, the 5-year survival rate of 17 who underwent adequate surgical treatment was 63%. The 5-year survival rate of the remaining 12 patients, including 5 with MFH of the pelvic bone who received inadequate or palliative surgery, was 17%. All six patients who received intensive chemotherapy combined with adequate surgical treatment were alive and well 5 years after the initial treatment. Histologically, the presence of desmoplasia and chronic inflammatory infiltration in the tumor tended to be prognostic indicators, although not to a statistically significant extent. Patients whose tumors contained wide areas of desmoplasia had a worse prognosis (5-year survival rate, 20%). In contrast, those with a prominent chronic inflammatory infiltrate had a 5-year survival rate of 78%.

CONCLUSIONS

These histologic variables would be helpful for predicting the prognosis of MFH of bone. Adjuvant intensive chemotherapy combined with adequate initial surgery may effect a clinical cure.