[Idiopathic spontaneous pneumomediastinum: a not to be mistaken diagnosis in chest pain].

We report two cases of mediastinal emphysema occurring without etiologic factor. Chest pain and subcutaneous emphysema are the most prevalent symptoms. In the absence of oesophagus related symptoms, a single chest radiograph is usually sufficient to make the diagnosis. In this paper, we recall the main radiographic signs, physio-pathological mechanisms, and differential diagnosis of spontaneous pneumomediastinum.