Lymphangiohemangiomas of the mediastinum are exceedingly rare. Clinically they tend to behave like lymphangiomas. We report 3 new cases. All 3 cases showed both lymphatic and vascular components. One case was associated with a left superior vena cava. In both other cases computed tomography with dynamic scans demonstrated the vascular components. Combined lymphatic venous malformation was thus evidenced in the 3 cases and supports that lymphangiohemangiomas are malformative in origin.