Primary malignant fibrous histiocytoma of the lung. Fine needle aspiration cytologic features.

A case of primary malignant fibrous histiocytoma of the lung occurring in a 71-year-old woman is presented. The preoperative aspiration cytology showed a large-cell, undifferentiated, malignant neoplasm suggestive of carcinoma. Subsequent histologic examination revealed a primary malignant fibrous histiocytoma. The diagnosis was confirmed by electron microscopic and immunohistochemical studies. Cytologic features of this rare primary pulmonary sarcoma are discussed.