metastatic myxoid liposarcomamyxoid liposarcoma histologymyxoid liposarcoma pathologymyxoid liposarcoma prognosismyxoid liposarcoma cancermyxoid liposarcoma pathology outlinesmyxoid round cell liposarcomadefine liposarcomamyxoid liposarcoma survival ratemyxoid sarcoma prognosismyxoid sarcoma cancermyxoid cells