Abstract
<jats:p>A 20 – year – old male without any previous comorbidity presented to pulmonary medicine outpatient department with complaints of dull aching chest pain on right side, dry cough and shortness of breath for the pastone year. He was non vegetarian and had no addictions. On general physical examination his vitals were stableand respiratory system examination revealed decreased breath sounds in the right hemithorax. All his routineblood investigations were normal. Chest radiograph revealed homogenous opacity in the right middle andlower zones. Contrast enhanced computed tomography of thorax and abdomen showed a well defined encapsulatedcystic lesion of size 12x10x14cm with internal floating membranes (water lily sign or Camelotte sign) with masseffect on adjacent lung parenchyma causing atelectasis and compression of adjacent vessels (Figure 1). Hydatid serology (IgG) was positive. Patient was treated symptomatically and referred for surgical intervention. </jats:p>