Chest Imaging

Lymphangioma

tumour-like congenital malformation of the lymphatic system. It consists of lymph channel or cystic lymph spaces lined by endothelium. Their walls are made of fibrous tissue and smooth muscle. They grow slowly and vary in size. They may demonstrate either a capillary or cavernous structure or a uni- or multilocular cystic appearance. These lesions do not undergo any malignant change. They may be difficult to resect because of envelopment or compression of adjacent structures. Typically lymphangiomas are located in the neck with an extension into the mediastinum. Most of them are discovered in infancy. Lymphangiomas confined to the mediastinum are rare, usually asymptomatic and incidentally discovered on chest radiographs in older children or adults.

On a chest radiograph, they appear as well-defined, round, lobular masses, usually in the anterior or superior mediastinum. A few may occur in the posterior mediastinum. Unilateral or bilateral pleural effusion may be present. In such situation, the fluid is often chylous (see chylothorax). CT or MR scans show a cystic mass sometimes multilocular or septated, which envelops or moulds to the adjacent mediastinal structures.

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