Postradiation pleomorphic malignant fibrous histiocytoma of the breast.

A case of primary malignant fibrous histiocytoma (MFH) of the breast occurring two years after surgical excision and radiation therapy for a carcinoma of the left breast is reported. Fine needle aspiration was positive for malignant cells, consistent with a pleomorphic sarcoma. Cytologic examination revealed giant cells with marked pleomorphism. Some cells showed single large nuclei with cytoplasmic vacuoles while others revealed multinucleation with foamy cytoplasm, phagocytosed erythrocytes and cellular debris. These findings are considered useful in the cytologic diagnosis of the pleomorphic variant of MFH.