A rare malignant neoplasm with melanocytic differentiation characterized by the presence of polygonal or spindle shaped clear cells. This sarcoma usually affects the tendons and aponeuroses and is associated with a poor prognosis due to recurrences and metastases. The disease is clear cell sarcoma (Monarch Disease Ontology term MONDO_0002926). Also known as: adult soft part clear cell sarcoma, chordoid sarcoma, clear cell sarcoma (morphologic abnormality), clear cell sarcoma - not kidney, clear cell sarcoma of soft parts, clear cell sarcoma of soft tissue, clear cell sarcoma/malignant melanoma of soft parts (excluding clear cell sarcoma of the kidney), malignant melanoma of soft tissues.