Extraskeletal myxoid chondrosarcoma of the thigh with a t(9;17) translocation

Abstract

Extraskeletal myxoid chondrosarcomas (EMC) are relatively rare. We report a case of EMC of the thigh. A 41-year old man presented with a tumor history of more than 4 months. Following open biopsy, wide resection of the tumor was performed. Histopathologically, the tumor had a multinodular architecture consisting of myxomatous areas demarcated by fibrous septa. Proliferation of uniform, round tumor cells with oval nuclei was observed. Well-formed hyaline cartilage and rhabdoid-like cells were not visible. Immunohistochemically, the tumor cells were positive for vimentin and S-100. The composite karyotype was 46,XY,t(9;17)(q22;q11),t(9;21) (q21;p13), and the diagnosis of EMC was made. No recurrence of the mass or metastasis was observed during a follow-up period of 4 years and 7 months. Only 50 cytogenetic cases of EMC, including our case, have been reported in the English literature thus far. Clinical presentation, radiological features and histopathological and cytogenetic findings are described, and the relevant literature is reviewed.