Primary malignant mesenchymoma of bone: case report, literature review, and distinction of this entity from mesenchymal and dedifferentiated chondrosarcoma

Composite sarcoma of bone with focal rhabdomyosarcoma and lymph node metastasis in an adolescent

Composite sarcoma of bone is a very rare entity that primarily affects adolescent and young adult patients. It usually combines areas of liposarcoma and osteosarcoma, and up to 60% of cases have metastatic disease at diagnosis. It is a highly aggressive pathology with intrinsic resistance to bone sarcoma conventional treatments. The prognosis is poor, with long-term survival rates not exceeding 30%. We present the case of an adolescent female diagnosed with an aggressive composite sarcoma of bone with rhabdomyosarcoma foci and loco-regional lymph node involvement.

Clinical outcomes for patients after surgery and radiation therapy for mesenchymal chondrosarcomas

INTRODUCTION

We report the outcome of 23 patients with mesenchymal chondrosarcomas treated with surgery and radiation therapy +/- chemotherapy. The intent of the project was to review the impact of patient and treatment variables on treatment outcome, in particular with regard to extent of surgery and radiation dose.

PATIENTS AND METHODS

Twenty-three patients with mesenchymal chondrosarcomas were treated with surgery and radiation therapy (min. dose 44 Gy; max. dose 78 Gy; median dose 60 Gy; mean dose 61 Gy).

RESULTS

The median survival for the entire cohort of patients was 21.65 years (95% confidence interval ± 4.25). The 5- and 10-year OS was 78.6%. Median disease-free survival for the 23 patients was 7.2 years. Disease-free survival (DFS) at 3 and 5 years was 70.7% and 57.8%, respectively. The local control rate at 5 and 10 years was 89.5% (95%CI 64.1-97.3%). Only three patients experienced local failure, three patients had regional failure, and eight developed distant metastases.

CONCLUSIONS

In this cohort of patients local tumor control was high when using a combination of surgery and radiation. There was not a clear relationship between radiation dose and local tumor control. J. Surg. Oncol. 2016;114:982-986. © 2016 Wiley Periodicals, Inc.

Malignant mesenchymoma in the nasal cavity of a bull

A 4-year-old bull was presented with facial distortion and abnormal respiratory noise. Endoscopically, a proliferative mass was found obliterating the left nasal cavity and a tumour was suspected. The head was examined after slaughter and there was a well-circumscribed solid structure (15×12×6 cm) extending into the paranasal sinus, the choanal region and the bones of the orbit, with focal penetration of the nasal septum. Microscopically, the mass consisted of well-differentiated trabeculae of woven and lamellar bone, areas of chondromyxomatous, immature and mature cartilaginous tissue, and regions with irregular whorled spindle cells. Tissue differentiation of the mass was variable. Centrally, there was osseous differentiation with an outermost fibromatous area resembling a zone of endochondral ossification. There was suppurative and ulcerative inflammation where the tumour extended through the hard palate and into the pharynx. A nasal malignant mesenchymoma was diagnosed on the basis of these features.

Primary osteochondrorhabdomyosarcoma (malignant mesenchymoma) of the fibula: a rare tumour in an unusual site - Case report and review of the literature. Case report

Malignant mesenchymoma, defined by Stout as sarcomas comprising two or more unrelated differentiated tissue elements other than a fibrosarcoma component, is rare. We report a case of primary malignant mesenchymoma of the proximal fibula in a 10-year-old female student who presented with pain and swelling of the right knee for 2 months. Initial biopsy showed features of rhabdomyosarcoma only, but the resected specimen revealed additional osteosarcomatous and chondrosarcomatous elements. The patient remained well more than 5 years after initial presentation. Including our present patient, 16 cases of primary malignant mesenchymoma of bone are found in the English literature, affecting mainly adolescents and young adults, with a slight male predominance and predilection for the metaphysis of long bones, especially around the knee. More than 60% of the patients develop metastasis, almost invariably to the lung, but occasionally to the brain. About 60% of the patients, all with metastasis, died mostly within one year of diagnosis. The clinical features of primary malignant mesenchymoma of bone thus resemble those of conventional osteosarcoma. Moreover, our case illustrates that, with combination chemotherapy targeted for individual elements, the prognosis of this rare tumour might be much improved, as in osteosarcoma.