Fine needle aspiration biopsy of primary malignant fibrous histiocytoma of the lung.

Malignant cells were found on the fine needle aspiration (FNA) biopsy smears from a primary tumor of the lung. The cytologic specimen contained a mixture of fibroblastlike cells, histiocytelike cells, giant cells and undifferentiated cells; mitotic figures were also found. Histologic, histochemical and electron microscopic studies confirmed the FNA cytologic suggestion of a primary malignant fibrous histiocytoma of the lung.