[The diagnosis of mediastinal lymphangioma in children].

On the basis of personal observation of four cases, the authors discuss the diagnostic aspects in this disease. Before birth, the diagnosis should be made by echography. After birth, magnetic resonance imaging scanning (IRM) is the method showing two types of cystic lymphangioma; a monomorphic and a polymorphic type. IRM is particularly valuable for the assessment of the extent of the disease all the more so as these tumours are often infiltrating. One should also recognise cervicomediastinal lymphangiomas which are more frequent in the very young and in whom the diagnosis is easy but one should not ignore the mediastinal component and those lymphangiomas which are purely mediastinal.