Collision tumor of a malignant fibrous histiocytoma and a pleomorphic adenoma in the parotid gland: A case report

In the pathological finding of this sarcoma, histiocytic cells, giant cells, and multinucleated giant cells with severe atypism were regularly distributed, with thin epithelium and fibrous composition. This finding led to a malignant fibrous histiocytoma subtype diagnosis. However, this sarcoma was neither clinically nor histopathologically a typical malignant fibrous histiocytoma. Therefore, we suggest that it was either an undifferentiated high-grade pleomorphic sarcoma or a carcinosarcoma with osteoclast-like giant cells.