Mesenchymal chondrosarcoma of bone and soft tissue: a systematic review of 107 patients in the past 20 years

Background

Mesenchymal chondrosarcoma(MCS) is a rare high-grade variant of chondrosarcoma. Consensus has not been reached on its optimal management. Resection with wide margins is usually recommended, but the effect of margins has been demonstrated by little positive evidence. Moreover, the effectiveness of adjuvant chemo- and/or radiotherapy remains controversial.

Objectives

To describe the clinical characteristics and outcomes of MCS of bone and soft tissue, to assess the efficacies of surgery, chemotherapy and radiation, and finally to deliver a more appropriate therapy.

Materials and Methods

We reviewed EMBASE-, MEDLINE-, Cochrane-, Ovid- and PubMed-based to find out all cases of MCS of bone and soft tissue described between April 1994 and April 2014. Description of treatment and regular follow-up was required for each study. Language was restricted to English and Chinese. Issues of age, gender, location, metastasis, and treatment were all evaluated for each case. Kaplan-Meier Method and Cox Proportional Hazard Regression Model were used in the survival analysis.

Results

From the 630 identified publications, 18 meeting the inclusion criteria were selected, involving a total of 107 patients. Based on these data, the 5-, 10-and 20-year overall survival are 55.0%, 43.5% and 15.7% respectively. The 5-, 10-, 20- year event-free survival rates are 45.0%, 27.2% and 8.1%, respectively. Treatment without surgery is associated with poorer overall survival and event-free survival. Negative surgical margins could significantly bring down the local-recurrence rate and are associated with a higher event-free survival rate. Chemotherapy regime based on anthracyclines does not benefit the overall survival. The addition of radiation therapy is not significantly associated with the overall or event-free survival. However, we recommend radiation as the salvage therapy for patients with positive margin so as to achieve better local control.

Conclusions

This review shows that surgery is essential in the management of MCS of bone and soft tissue. Appropriate adjuvant therapy may reduce local recurrence, but cannot benefit the overall survival.

An unusual case of primary mesenchymal chondrosarcoma in orbit with intracranial extension

An unusual case of primary orbital mesenchymal chondrosarcoma with intracranial extension is reported, with special emphasis on the radiological findings.

The clinical approach towards chondrosarcoma

This review provides an overview of the histopathology, classification, diagnostic procedures, and therapy of skeletal chondrosarcoma. Chondrosarcomas that arise de novo are primary chondrosarcomas, whereas chondrosarcomas developing superimposed on pre-existing benign cartilage neoplasms such as enchondromas or osteochondromas are referred to as secondary chondrosarcomas. Conventional chondrosarcomas can be categorized according to their location in bone into central, peripheral, and juxtacortical chondrosarcomas. Histological grading is related to prognosis; however, it is also subject to interobserver variability. Rare subtypes of chondrosarcoma, including dedifferentiated, mesenchymal, and clear cell chondrosarcoma, are discussed as well. Magnetic resonance imaging is necessary to delineate the extent of the intraosseous and soft tissue involvement preoperatively. Computed tomography is especially recommended in the pelvis and other flat bones where it may be difficult to discern the pattern of bone destruction and the presence of matrix mineralization. Wide, en-bloc excision is the preferred surgical treatment in intermediate- and high-grade chondrosarcoma. In low-grade chondrosarcoma confined to the bone, extensive intralesional curettage followed by local adjuvant treatment and filling the cavity with bone graft has promising long-term clinical results and satisfactory local control. Chondrosarcomas are relatively radiotherapy resistant; therefore, doses >60 Gy are needed in attempts to achieve local control after incomplete resection. Irradiation with protons or other charged particles seems beneficial in this curative situation. Chemotherapy is only possibly effective in mesenchymal chondrosarcoma, and is of uncertain value in dedifferentiated chondrosarcoma. Potential new systemic treatment targets are being discussed.

BNCT for recurrent intracranial meningeal tumours - case reports

OBJECTIVES

The investigation was designed to explore the efficacy of boron neutron capture therapy (BNCT) as treatment for recurrent intracranial meningeal tumours.

MATERIALS AND METHODS

Three patients with meningeal tumours, recurring after initial surgery, radiation therapy and several reoperations, were evaluated for treatment with BNCT by determination of the accumulation of boronophenylalanine fructose (BPA-F) in tumour and in surrounding tissue. Two of these patients were subsequently treated by BNCT.

RESULTS

The present results indicate that BNCT could be effective in prolonging time to recurrence, and thus in extending survival time, for patients with recurrent intracranial meningeal tumours.

CONCLUSIONS

BNCT is potentially an effective radiation treatment modality for malignant intracranial meningeal tumours, which could increase progression-free survival, thus reducing the need for additional surgical interventions. Indications for BNCT would be even larger if recurrent grade II meningiomas could be treated, as indicated by the results of the boron uptake study.

Extraskeletal mesenchymal chondrosarcoma of the forearm: a case report

Mesenchymal chondrosarcomas represent less than 10% of all chondrosarcomas. The majority of these tumors arise from the skeleton; only 22% have an extraosseous origin. Of the extraskeletal locations, the meninges, brain, and thigh are the most common. Involvement of the forearm is a rare occurrence. This case report describes an extraskeletal mesenchymal chondrosarcoma involving the forearm.

Mesenchymal chondrosarcoma of the orbit

PURPOSE

To describe a patient with mesenchymal chondrosarcoma of the orbit, review clinical and imaging findings, and refine the differential diagnosis from other tumors of the orbit.

METHODS

Interventional case report and literature review.

RESULTS

A 21-year-old woman with a 6-month history of progressive proptosis presented with left-sided visual loss of recent onset. CT revealed a clearly outlined heterogeneous mass with calcified foci, whereas MRI showed an isointense signal to gray matter on T1- and T2-weighted images. The patient was diagnosed with mesenchymal chondrosarcoma of the orbit only after orbitotomy and subsequent histopathologic study. After surgery, she received adjuvant therapy with irradiation of the orbit.

CONCLUSIONS

Mesenchymal chondrosarcoma is a rare malignant tumor of the orbit capable of mimicking several other lesions. Early diagnosis requires a high level of suspicion, particularly with regard to internally calcified lesions. The treatment of choice is complete surgical resection, or, when the tumor is not resectable or residual mass is present after surgery, chemotherapy and radiotherapy. Prognosis for patients with orbital mesenchymal chondrosarcoma is tentative at best, in part because of the rarity of the lesion.

Mesenchymal chondrosarcoma of the temporal bone

A 64-year-old patient with mesenchymal chondrosarcoma of the temporal bone is described. CT and MRI showed an extensive mass with calcification involving the temporal bone and extending into the middle cranial fossa and nasopharynx. The tumor was ill-defined from surrounding normal bone, and a subtotal petrosectomy was carried out. The nasopharyngeal extension was removed secondarily using an endoscope. The clinical and diagnostic aspects and management of this rare lesion are discussed.

Computer-aided design and fabrication of an electron bolus for treatment of the paraspinal muscles

PURPOSE

Demonstrate the technology for the design, fabrication, and verification of an electron bolus used in the preoperative irradiation of a mesenchymal chondrosarcoma in the paraspinal muscle region (T8-T12), in which the target volume overlay a portion of the spinal cord, both lungs, and the right kidney.

METHODS AND MATERIALS

An electron-bolus design algorithm implemented on a three dimensional (3D) radiotherapy treatment planning system designed the bolus to yield a dose distribution that met physician-specified clinical criteria. Electron doses were calculated using a 3D electron pencil-beam dose algorithm. A computer-driven milling machine fabricated the bolus from modeling wax, machining both the patient surface and the beam surface of the bolus. Verification of the bolus fabrication was achieved by repeating the patient's computed tomography (CT) scan with the fabricated bolus in place (directly on the posterior surface of the prone patient) and then recalculating the patient's dose distribution using the 3D radiotherapy treatment planning system.

RESULTS

A treatment plan using a 17-MeV posterior electron field with a bolus delivered a superior dose distribution to the patient than did the same plan without a bolus. The bolus plan delivered a slightly increased dose to the target volume as a result of a slightly broader range of doses. There were significant reductions in dose to critical structures (cord, lungs, and kidney) in the bolus plan, as evidenced by dose-volume histograms (DVHs). The patient dose distribution, calculated using CT scan data with the fabricated bolus, showed no significant differences from the planned dose distribution.

CONCLUSIONS

A bolus can provide considerable sparing of normal tissues when using a posterior electron beam to irradiate the paraspinal muscles. Bolus design and fabrication using the tools described in this paper are adequate for patient treatment. CT imaging of the patient with the bolus in place followed by calculation of the patient's dose distribution demonstrated a useful method for verification of the bolus design and fabrication process.