[Extraskeletal myxoid chondrosarcoma of the left iliopsoas muscle]

A 62-year-old man was referred to our hospital with a 10 cm retroperitoneal tumor, which was incidentally found on the abdominal computed tomography (CT). CT-guided percutaneous needle biopsy revealed that the tumor was malignant, but could not define the exact pathology of the tumor. The tumor was resected. The pathological study revealed atypical spindle to polygonal shaped cells embedded in the myxomatous stroma. The tumor was diagnosed as extraskeletal myxoid chondrosarcoma. Walking difficulty was observed postoperatively, which was considered to have been caused by damage of a branch of the femoral nerve. The difficulty had gradually overcome with rehabilitation before discharge.