Extraskeletal myxoid chondrosarcoma with dedifferentiation - A case report

Background: Extraskeletal myxoid chondrosarcoma is an uncommon tumor, whose histogenesis is controversial. Case Report: A 55-year-old female patient presented with a gradually enlarging swelling in the thigh. Based on the histopathological features and immuno histochemistry, a diagnosis of extraskeletal myxoid chondrosarcoma was made. There were two unusual features in the case. Dedifferentiated areas of malignant fibrous histiocytoma were seen juxtaposed with the myxoid chondroasarcomatous areas. In addition, the tumor cells exhibited neural markers like neuron specific enolase and S-100. Conclusions: Dedifferentiation is a rare feature of extraskeletal myxoid chondrosarcoma. The expression of neuron specific enolase and S-100, is in accordance with recent studies which demonstrate some neural/neuroendocrine markers in these tumors, raising further questions regarding the histogensis of this uncommon tumor.