Fibrosarcoma and malignant fibrous histiocytoma of long bones: radiographic features and grading

Local irradiation in combination with bevacizumab enhances radiation control of bone destruction and cancer-induced pain in a model of bone metastases

Skeletal metastases are a major source of morbidity for cancer patients. The purpose of this study was to evaluate the effects of megavoltage irradiation and antiangiogenic therapy on metastatic bone cancer. A tumor xenograft model was prepared in C3H/Scid mice using 4T1 murine breast carcinoma cells. Twenty-eight mice bearing tumors were treated with either bevacizumab (15 mg/kg), local megavoltage irradiation (30 Gy in 1 fraction), combination of bevacizumab and local megavoltage irradiation or physiologic saline solution (control group). Tumor area, bone destruction, tumor microvessel density, pain-associated behaviors and expression of substance P were assessed. Combined modality treatment reduced the frequency of pain-associated behaviors, decreased levels of nociceptive protein expression in the spinal cord, maintained cortical integrity and decreased the density of microvessels as compared to single modality treatments. We conclude that concurrent antiangiogenic therapy and localized radiotherapy for the treatment of bone metastases warrants further evaluation in human clinical trials.

Limb salvage surgery complimented by customised mega prostheses for malignant fibrous histiocytomas of bone

PURPOSE

To assess functional and oncological outcomes of patients with malignant fibrous histiocytomas of bone, after limb salvage surgery complimented by a customised prosthesis.

METHODS

Between May 1991 and December 2002, 15 men and 5 women (mean age, 42 years) with histologically proven malignant fibrous histiocytoma of bone underwent treatment involving limb salvage surgery complimented by a customised mega prosthesis. Most of the tumours were stage II according to the Enneking system, and located around the knee. Wide resection margins were achieved in 18 patients.

RESULTS

Following a mean follow-up of 58 months, 4 patients underwent amputation for local recurrence and 5 died of the disease. Two patients had prosthesis fractures; revision of the prosthesis was carried out in one. The functional result was excellent in 5 and good in 9 patients. The Kaplan-Meier 5-year survival rates of the patients treated without chemotherapy and with chemotherapy were 50% and 76%, respectively.

CONCLUSION

Limb salvage surgery with chemotherapy is a viable treatment option for patients with malignant fibrous histiocytoma of bone. It achieves higher survival rates than resection alone. Such therapy improves quality of life and provides a useful and functional limb.

Genetic analysis of fibrosarcoma of bone, a rare tumour entity closely related to osteosarcoma and malignant fibrous histiocytoma of bone

Fibrosarcoma (FS) of bone is an extremely rare and genetically uncharacterised malignant tumour arising in the skeleton. On the basis of clinicopathologic features it appears to be closely related to either fibroblastic osteosarcoma (OS) or malignant fibrous histiocytoma (MFH) of bone. In this study, 27 decalcified, paraffin-embedded FS of bone were collected for genetic and immunohistochemical characterisation. Good quality DNA, suitable for genetic analyses, was isolated from nine cases (7 primary tumours, 1 local recurrence, and 1 lung metastasis), which were analysed by comparative genomic hybridisation (CGH) on chromosomes and DNA microarrays. DNA sequence copy number changes were found in five out of seven primary tumours (72%), as well as in both, the local recurrence and the metastatic lesion, by CGH on chromosomes. The most frequent aberration was gain of the chromosomal region 22q, which was present in four out of the five primary tumours with genetic changes, in the local recurrence and, as the sole genetic aberration, in the lung metastasis. DNA microarray analysis showed that gain of the platelet-derived growth factor beta (PDGF-B) gene (located at 22q12.3-q13.1) was the most frequent gene imbalance, which was present in three out of the five analysed tumours. In these three cases, real-time PCR revealed a 2.1- to 2.7-fold increase of PDGF-B gene copy numbers. By immunohistochemistry, a positive reaction for B-chain-containing PDGF proteins was revealed in all the cases showing gain of 22q. A more extensive immunohistochemical analysis identified the presence of PDGF-B proteins in 8/20 primary FS of bone (40%), 3/3 lung metastases and in 1/2 local recurrences. A simultaneous positive reaction for PDGF-B proteins and PDGF receptors was found in two third of PDGF-B-positive cases (8/12). Taken together, the genetic and immunohistochemical data indicate that over-representation of the chromosomal region 22q, including particularly the PDGF-B gene, may be important for the pathogenesis of FS of bone. Our results also demonstrate that CGH on chromosomes and DNA microarrays are suitable for the genetic characterisation of decalcified, paraffin-embedded tumour tissue samples and may facilitate, combined with other techniques, the rapid acquisition of data providing insight into the molecular genetic and biologic basis of rare bone sarcomas. Moreover, these findings suggest the possible presence of an autocrine loop in FS of bone, which might be taken into account for planning innovative therapeutic strategies for patients unresponsive to conventional treatments.

Low-grade fibrosarcoma of the proximal humerus

We present the clinical, radiographical and pathological features of low-grade fibrosarcoma of the left proximal humerus in a 23-year-old man in whom it was necessary to distinguish the tumor from desmoplastic fibroma, malignant fibrous histiocytoma and intramedullary well-differentiated osteosarcoma. The patient presented with a 10-day history of pain in his left upper arm sustained when trying to break his fall with his left hand when slipping in the street. Plain radiography revealed an expanding multilobular osteolytic lesion from the proximal metaphysis to the diaphysis of his left humerus, accompanied by a pathological fracture at the distal portion of the lesion. Open biopsy of the lesion was performed twice; however, a conclusive diagnosis could not be obtained. The patient underwent wide excision and prosthetic replacement of the left proximal humerus. Histologically, the resected tumor was composed of both cellular areas and hypocellular areas. Cellular areas revealed a proliferation of bundles of uniform fibroblastic spindle-shaped cells with minimal cellular atypia, mixed with abundant intercellular collagenization. Mitotic figures were occasionally seen. Hypocellular areas showed myxoid features with loose bundles of collagen fibers. The patient demonstrates no evidence of disease 42 months after surgery. It is important to detect the scant atypical cells for the differential diagnosis of low-grade fibrosarcoma and desmoplastic fibroma of bone.

Fibrosarcoma of the jaws

The records of 14 patients with fibrosarcoma of the jaws--10 in the mandible and four in the maxilla--from the files of the Netherlands Committee on Bone Tumours were studied. The mean age of the patients was 30 years; more men than women were involved; pain and especially swelling were the symptoms most frequently present. The radiographic appearance often indicated the malignant nature of the lesion. Histologically 42% of the tumours were low-grade malignant. The 5-year survival rate was 71%, which is more favourable than either fibrosarcoma located elsewhere in the skeleton or osteosarcoma of the jaws. Radical surgery is the therapy of choice. All cases with an unfavourable course acquired lung metastases.