Disseminated malignant fibrous histiocytoma (giant cell rich): a case report.

Giant cell rich malignant fibrous histiocytoma accounts for 3 -15% of all malignant fibrous histiocytomas. Currently, the nomenclature giant cell malignant fibrous histiocytoma is reserved for undifferentiated pleomorphic sarcomas with prominent osteoclastic giant cells. It is considered to be synonymous with malignant giant cell tumor of soft parts. We report a case of disseminated giant cell malignant fibrous histiocytoma involving the scalp, cervical node, lungs, spine, abdominal wall, base of penis, gluteal cleft, paraspinal region and back. The diagnosis was established after staining for a panel of immunohistochemical markers namely cytokeratin, vimentin, S100, desmin, CD68 and smooth muscle actin. CD68 positivity in tumor cells helped in arriving at the final diagnosis. It is essential to recognize this tumor as a giant cell rich distinct entity and differentiate from other giant cell rich pleomorphic sarcomas since therapeutic and prognostic differences are being appreciated currently.