[Primary giant cell malignant fibrous histiocytoma of the lung].

A case of primary giant cell malignant fibrous histiocytoma (MFH) of the lung was reported. Gross findings showed two well demarcated isolated nodules located in the right lower lobe of the lung appeared yellowish-gray and gray-red on gross section with areas of focal calcifications, hemorrhage and necrosis. Microscopic findings showed that the tumor consisted of diffuse neoplastic histiocytes and spindle-shaped fibroblasts arranged in a prominent storiform pattern intermingled with numerous multinucleated tumor giant cells and osteoclast-like multinucleated giant cells. Focal osteoid tissue was mainly located at the periphery of the tumor. In addition, a number of scattered apoptotic multinucleated giant cells were observed. Tumor cells were positive for vimentin, alpha-1-antitrypsin, lysozyme and mac387, but negative for cytokeratin, actin, S-100, NSE, and NF. Primary giant cell MFH of the lung is a very rare malignant tumor. This tumor should be treated by prompt radical surgery.