[Lymphangioma and lymphangiectasia].

Primary thoracic lymphatic diseases are both infrequent and probably under diagnosed. The two major forms are lymphangiomas and lymphangiectasias. Lymphangiomas are focal proliferation of well-differentiated lymphatic vessels. Childhood lymphangiomas may follow embryologic disorders. Adult lymphangiomas are more likely secondary to lymphatic obstruction. When associated with typical CT and MRI features, their surgical resection is not mandatory, whereas in case of diagnostic difficulties or related complications, surgical resection is the rule. Lymphangiectasias are congenital or acquired pathologic lymphatic dilatation from pleura and interlobular septa without any proliferation. These diseases can be limited to one pulmonary lobe, or can involve the whole lymphatic network. In case of communication between the lymphangiectasias and the thoracic duct, symptoms may include chyloptysis, chylothorax, and chylopericardium. Lymphangio MRI allows visualisation of the lymphangiectasis and thoracic duct. Surgical treatment may be required in case of resistance to medical treatment.