Primary leiomyosarcoma of the aorta.

A case of primary leiomyosarcoma of the abdominal aorta is reported. The tumor replaced the full thickness of the aortic wall with formation of a large saccular aortic aneurysm filled with an admixture of tumor and mural thrombus. Electron microscopy of the surgical biopsy of the tumor revealed neoplastic smooth muscle cells with myofilaments and a discontinuous basal lamina. To our knowledge, leiomyosarcoma of the aorta has never been reported.