Follicular dendritic cell sarcomas of mediastinum are very rare neoplasms. We report this rare case 49-year-old woman with a mass with the localization in anterior mediastinum extending to visceral part of mediastium. Computed tomography revealed, a 9x8x8 centimeters diameter smoothly marginated mass lesion. It was contiguous with the arcus aorta, left pulmonary trunk, truncus of left pulmonary artery, left brachiocephalic vein and left subclavian artery. The tumor was completely removed by median sternotomy. Intraoperatif findings were an anterior mediastinal mass. The histopathological analysis revealed a follicular dendritic cell sarcoma, a rare intermediate grade malignancy neoplasm.