Water lily appearance in chest X-ray suggestive of the following condition:
Chest X-ray finding of hydatid cyst of the lung: Dense homogenous opacity Collapsed laminated membrane produces an irregular projections in a fluid level due to rupture of the cyst- 'Water-lily appearance' Crescentic cap of air, when it communicates into bronchial tree Ref: Srb's Manual of Surgery By Bhat, 2012, Page 1205.
Bronchiectasis
Bronchopleural fistula
Hydatid cyst
Sequestration cyst of lung