Cystic lymphangioma of the mediastinum.

Cystic lymphangioma is a rare congenital benign tumor. It results from focal proliferation of well-differentiated lymphatic tissue originating from abnormal development of the lymphatic system. Most cystic lymphangiomas occur in the primitive lymph sacs of children or young adults. They generally appear in the neck (75%) and axillary region (20%). Only 1% are located in the mediastinum. Acquired lymphangiomas, which are principally seen in middle-aged adults, are caused by a process of chronic lymphatic obstruction secondary to surgery, chronic infection, or radiation. Here, we present the case of a 50-year-old male with cystic lymphangioma of the mediastinum, detected on a routine chest X-ray.