[Malignant fibrous histiocytoma of the lung].

A 68-year-old man had a malignant fibrous histiocytoma of the lung that was found at autopsy. The patient was admitted to our hospital because of exertional dyspnea. A chest X-ray film and chest CT scan showed atelectasis in the left upper lobe. Examination with a fiberoptic bronchoscope revealed a necrotic mass in the left mainstem bronchus. Microscopic examination of a biopsy specimen disclosed several atypical giant cells but was not diagnostic. He underwent chemotherapy with CBDCA, IFM and VP-16, because a malignant tumor of the lung was strongly suspected. After three cycles of chemotherapy, the tumor had shrunk, as demonstrated on repeated bronchoscopy. The patient's condition improved temporarily, but he began to complain of dyspnea, and died of respiratory insufficiency despite radiotherapy. Postmortem examination was done. The tumor in the lung was mainly composed of spindle-shaped fibroblast-like cells and several pleomorphic giant cells with multiple nuclei, with storiform and fascicular patterns. Immunohistochemically, these tumor cells were shown to contain vimentin, alpha-1-antitrypsin, and LN-5. These findings were compatible with malignant fibrous histiocytoma of the lung.