A 30 year old man came with complaints of chronic cough and shortness of breath since six months
The chest radiograph shows a thin walled cavity in the left lower zone with an air fluid level.Both the costophrenic angles are normal. The cardiac silhouette is obscured on the left side. Contrast enhanced CT scan of the chest shows a well-defined, round, cystic lesion in the left perihilar - middle mediastinumwith an air-fluid level. It has thin walls measuring and 7 x 8.0 x 7.0 cm.