A rare malignant soft tissue neoplasm of uncertain differentiation, characterized by the presence of chondroblast-like cells in a myxoid stroma and a multinodular growth pattern. The most common sites of involvement are the deep soft tissues of the extremities, particularly the thigh. It usually presents as an enlarging soft tissue mass. Patients may have long survivals, but local recurrences and metastases occur in approximately half of the cases. The most common site of metastasis is the lungs. The disease is extraskeletal myxoid chondrosarcoma (MONDO_0012825, a Monarch Disease Ontology identifier). Also known as: extraosseous chondrosarcoma, extraskeletal chondrosarcoma, myxoid extraosseous chondrosarcoma, myxoid extraskeletal chondrosarcoma.