An undifferentiated soft tissue sarcoma characterized by the presence of a pleomorphic malignant cellular infiltrate. It is also known as malignant fibrous histiocytoma. The disease is undifferentiated pleomorphic sarcoma (MONDO_0002142). Also known as: MFH, Storiform-pleomorphic MFH, Storiform-pleomorphic fibrous histiocytoma, Storiform-pleomorphic malignant fibrous histiocytoma, UPS, Unclassified Pleomorphic sarcoma (formerly "MFH"), Unclassified Pleomorphic sarcoma (formerly "malignant fibrous histiocytoma"), adult malignant fibrous histiocytoma.