Malignant fibrous histiocytoma of the spine: a series of 13 clinical case reports and review of 17 published cases.

STUDY DESIGN

Retrospective case study of 13 primary malignant fibrous histiocytomas (MFH) of the spine.

OBJECTIVE

To analyze the clinic, radiologic, histologic, and prognostic features of 13 cases with the MFH of the spine.

SUMMARY OF BACKGROUND DATA

MFH, a soft tissue sarcoma, rarely occurs at the spine. Only sporadical cases have been reported in the English literature concerning the clinical and prognostic features of the primary MFH at the spine.

METHODS

Between January 1999 and December 2006, 13 cases with primary MFH of the spine were treated in the authors' spine center. Clinical history, radiographic, surgery resection, and pathologic features were recorded. The patients were followed up regarding their local recurrence and survivals. The 17 cases with primary MFH at the spine in the literature were reviewed.

RESULTS

Paraspinal or epidural mass at multiple spinal levels developed in 11 cases, with osteolytic destruction in all 13 cases. The tumor size averaged on 10.4 cm in greatest dimension. Metastases occurred in 10 of 13 cases. Compared with the 14 ± 0.60-months median survival of the debulking surgeries in seven cases, the median survival of the en bloc resection in six cases was 25 ± 6.12 months (P ∇ 0.009). The median survival was 8.7 months in 10 cases of the literature group, with 30% 1-year survival and 6.7% 2-year survival, respectively; while the median survival was 18.0 months in the authors' series, with 92.3% 1-year survival and 38.5% 2-year survival, respectively. The 5-year survival was between 25% and 69% in the extremities of MFH, but it was 28% in the head and neck and 26.7% in the abdominal cavity, compared with 7.7% in the spine in the authors' series.

CONCLUSION

The MFH of the spine tends to extensively invade paraspinal structures at multiple spinal levels, with aggressive osteolytic destruction in the vertebrae, resulting to local huge mass, radiculopathy, and myelopathy. Regardless of recent advancements in the diagnosis, treatment methods, and adjuvant therapies, for its biologically aggressive nature, it frequently recurs at the primary site and metastasizes. It has a worse prognosis than that of MFH in other sites.