Metastatic or multicentric? A report of what we believe to be a case of multicentric extraskeletal mesenchymal chondrosarcoma

Mesenchymal chondrosarcoma represents less than 0.4% of all malignant musculoskeletal tumors. Extraskeletal mesenchymal chondrosarcomas, which have no topographic relationship to a bone, can arise in any tissue such as bladder, muscles, arteries, etc. We report a case of a 25-year-old male with extraskeletal mesenchymal chondrosacomas of the quadriceps muscle and orbit, with rapid progression, cutaneous and bone metastases and lethal exitus within 11 months of the first clinical signs. According to clinical course and immunocytopathological findings, we strongly believe that this report could be a case of extraskeletal mesenchymal chondrosarcoma with a multicentric origin.