Extraskeletal myxoid chondrosarcoma of the knee

Extraskeletal myxoid chondrosarcoma is an uncommon neoplasm, accounting for less than 2% of all soft tissue sarcomas. It affects adult males with a me dian age in the fifth decade at the time of diagnosis, The tumor usually ar ises in the deep soft tissues, especially in the lower extremities. Patient s present with a gradually enlarging mass that may or may not be associated with pain. This report describes a 25-year-old man who initially presented with a 4- to 5-year history of right knee pain and an enlarging mass in th e right knee. Evaluation revealed a cartilaginous neoplasm with no evidence of metastatic disease. The tu mor was widely excised and an allograft reco nstruction was performed. The patient was closely followed with an eventual above the knee amputation for recurrent myxoid chondrosarcoma. At 34 month s, retroperitoneal metastases were noted on abdominal CT. The patient under went a left radical nephrectomy, renal vein thrombectomy and enucleation of the mass in the right kidney, distal pancreatectomy, and splenectomy, The patient received postoperative chemotherapy. Forty-eight months after initi al diagnosis, the patient was found to have recurrent abdominal and retrope ritoneal lesions. At 64 months, the patient died from complications of extr askeletal myxoid chondrosarcoma.