Benign blood vascular tumors of the mediastinum. Report of four cases and review of the literature.

The authors present 4 new cases and review 77 previously reported cases of benign blood vascular tumors of the mediastinum. The vast majority are hemangiomas (90%), occur in the first four decades of life (75%), and arise in the anterior mediastinum (68%). Compression and/or invasion of adjacent structures is not uncommon. Concomitant extrathoracic extension (2%) and multiple sites of involvement (2%) are rare. The tumors are smoothly outlined, occasionally lobulated and can be accurately identified when phleboliths are present (10%).