Asymptomatic congenital oesophageal cyst infiltrating the lung: an unusual complication.

An asymptomatic 14-year-old boy presented with minor chest trauma. Chest X-ray showed opacity in the upper zone of the left lung. Further investigations with magnetic resonance imaging showed it to be a posterior mediastinal mass with a fistula to the lung, along with cystic changes in the left upper lobe of lung. Left upper lobectomy with excision of the mass was performed. Histological examination later showed an oesophageal duplication cyst with a fistula to the left upper lobe of the lung. We present this unusual complication of an oesophageal cyst infiltrating the lung in an asymptomatic child.