Undifferentiated Pleomorphic Sarcoma With Giant Cells
Khin Thway, BSc, MBBS, FRCPath
Key Facts
Terminology
Malignant pleomorphic spindle and polygonal cell sarcoma with osteoclast-type giant cells
Tumor morphology shared with several other pleomorphic malignant tumors of different lineages
Clinical Issues
Older adults
Mostly in deep soft tissue
Extremity or trunk
Microscopic Pathology
Sheets of markedly atypical spindle and polygonal cells
Prominent intermixed osteoclast-type giant cells that lack atypia
Ancillary Tests
As morphology is shared by other tumors of different lineages, features of specific differentiation need exclusion
 Osteoclast-like giant cells are admixed with tumor cells in this example of giant cell MFH. The giant cells show plump nuclei with prominent nucleoli but lack the pleomorphism and marked atypia of the tumor cells. |
 Osteoclast-like giant cells  and tumor giant cells  are often intermingled. Note the much larger size of tumor nuclei compared to those of the giant cells. |
TERMINOLOGY
Abbreviations
Giant cell malignant fibrous histiocytoma (MFH)
Synonyms
Malignant giant cell tumor of soft parts
Giant cell sarcoma
Malignant osteoclastoma
Pleomorphic undifferentiated sarcoma with giant cells
Definitions
Malignant pleomorphic spindle and polygonal cell sarcoma with osteoclast-type giant cells
Morphology shared with several other pleomorphic malignant tumors of other lineages
CLINICAL ISSUES
