Cystic lymphangioma is a rare congenital benign tumor, generally considered as the local proliferation of differentiated lymphoid tissue in the development of the lymphatic system. This disease occurs in various areas of the body, with the most common location at the neck, occasionally the axilla or groin, and rarely in the mediastinum. 

Patients with mediastinal cystic lymphangioma usually have no specific symptoms. Most cystic lymphangiomas are not diagnosed during childhood until they grow very large.  Aspiration biopsy, which is prohibited if pulmonary echinococcosis is suspected, improves the diagnostic rate of the disease, but the final diagnosis requires histopathologic examination of the resected specimen. Thymic cysts, Castleman’s disease, bronchogenic cysts, pericardial cysts, cystic teratomas and pulmonary echinococcosis should be kept in mind in the differential diagnosis of cystic lymphangioma.

CT and lymphangiography are helpful in determining the extent of the disease, the size of the cyst, and the lymphatic nature of the mass. Magnetic resonance imaging (MRI) is also used to demonstrate the relationship of the mass with the surrounding structures 

Malignant transformation of cystic lymphangioma has not been reported, but complete surgical resection is generally recommended. Traditionally, surgical resection was performed via open thoracotomy. With the development of minimally invasive techniques, several studies have focused on VATS for the treatment of mediastinal cystic lymphangioma. VATS for treatment of mediastinal lymphangioma remains difficult, and complete excision still remains to be technically problematic because of the peripheral adhesions of the tumor. These should be carefully managed to avoid injuries of azygos vein, aorta, bronchus, recurrent laryngeal nerve, phrenic nerve, etc. The objective of the operation should be the complete resection of the lesion, because incomplete resection can result in recurrence of the cyst.