Arterio-veno-lymphatic vascular malformation presenting as an anterior mediastinal mass

Mediastinal lymphatic venous malformation (LVM) is considered tumor-like vascular dysplasias that are rarely found in the mediastinum. Clinical presentation of LVMs varies depending on the patient. Patients may be asymptomatic or may present with symptoms such as cough, chest pain, dyspnea, and hemoptysis. A 4-year-old girl was admitted to the hospital with complaints of coughing attacks, shortness of breath in the right lateral decubitus position, and restlessness. A contrast-enhanced thorax computed tomography scan was performed to evaluate the relationship between the major mediastinal vascular structures and the mass. A left anterolateral thoracotomy was performed. The pathology was reported as an arterio-veno-lymphatic vascular malformation. Mediastinal LVMs are extremely rare but may present with severe life-threatening symptoms due to compression of major mediastinal structures. This report highlights that mediastinal LVM has a differential diagnosis and its management can be challenging.