True aneurysms in a saphenous vein graft placed for repair of a popliteal aneurysm: etiologic considerations.

Although vein graft aneurysms have been described to be atherosclerotic in nature, it has been hypothesized that vein graft aneurysms may be a part of a systemic dilating process. In the case reported here, histopathologic examination of vein graft aneurysms demonstrates aneurysmal degeneration with no atherosclerotic changes and do support the hypothesis that vein graft aneurysms may be a manifestation of a systemic dilating process.

Mediastinal myelolipoma.

Myelolipoma is a rare tumor, and a mediastinal location is extremely unusual. The main pathologic feature is the coexistence of mature adipose tissue and bone marrow cells; the presence of megakaryocytes is essential for diagnosis. The successful removal of a mediastinal myelolipoma in a 59-year-old man is described.