We report the case of a 35-year-old patient with an incidental finding of an asymptomatic large (9.5 cm in diameter) anterior mediastinal tumour. Radiological findings favoured the diagnosis of a benign mediastinal teratoma. During surgical resection, we found a tumour adhering to the surrounding tissues, and encompassing the innominate vein which was totally occluded. Total tumoural exeresis was performed as well as the double cross-section of the innominate vein. Postoperatively, there was no left upper limb swelling, probably because of a chronic occlusion of the innominate vein. The hospital stay was uneventful. Immunohistochemistry diagnosed a mediastinal 'epithelioid haemangioendothelioma', which is a tumour of vascular origin. We believe that the tumour took origin from the innominate vein and invaded the anterior mediastinum. After a simple radiological follow-up, the patient is in complete remission 30 months after the operation. We present the case of this patient with the iconography, along with a review of the available literature concerning mediastinal epithelioid haemangioendotheliomas.