undifferentiated pleomorphic sarcoma undifferentiated high grade pleomorphic sarcoma of bone https://www.malacards.org/card/malignant_fibrous_histiocytoma_of_bone GARD:0023190 malignant fibrous histiocytoma of the bone DOID:3352 malignant fibrous histiocytoma of bone NCIT:C8563 UMLS:C0740479 MEDGEN:149264 undifferentiated high-grade pleomorphic sarcoma malignant bone fibrous histiocytoma MONDO:0002618 undifferentiated high grade pleomorphic sarcoma A rare, high-grade pleomorphic malignant neoplasm arising from the bone. It usually presents with pain which may or may not be associated with swelling in the affected area. It is characterized by the presence of spindle-shaped cells, polygonal or epithelioid cells, multinucleated giant cells, and inflammatory cells. The neoplastic cells exhibit nuclear pleomorphism and high mitotic activity. It metastasizes frequently, most often in the lungs. undifferentiated high grade pleomorphic sarcoma of bone osteosarcoma bone sarcoma