Key Points

• Cystic lesions in the mediastinum are uncommon in infants and children
• Most cystic lesions in infants and children are benign
• Symptoms from the cystic lesions arise from mass effect on adjacent structures or infectious and inflammatory complications
• Complete surgical excision is required for any symptomatic mediastinal cyst unless there is a common wall to the airway or esophagus of a foregut cyst
• Prenatal diagnosis of cystic lesions warrant consultation with a multi-disciplinary team, especially for cases involving fetal distress