Solitary fibrous tumors of the pleura presenting satellite tumors.

A 29-year-old man presented with a mass in the left lower lung field on a chest radiograph obtained during a medical checkup. Computed tomography revealed a tumor adjacent to the diaphragm. A sessile tumor measuring 10.5 x 8.5 x 4.5 cm arising from the parietal pleura was resected. The tumor was accompanied by several little tumors on the nearby diaphragm. Pathologically, the major tumor consisted of typical spindle-shaped cells with myxoid degeneration. There was no increased cellularity, cellular pleomorphism, or a high mitotic count. In immunohistochemical studies, the spindle cells showed positive staining for CD34 and were negative for bcl-2. The smaller tumors also consisted of myxoid degeneration. We diagnosed benign solitary fibrous tumor of the pleura with satellite tumors. We must be aware of the possibility of satellite tumors when we treat patients with a benign solitary fibrous tumor.