050. Water-lily sign in a patient without ruptured lung hydatid cyst

Background: Our aim was the presentation of a case with clinico-radiologic findings compatible with ruptured echinococcus cyst that was not finally confirmed.

Case presentation: A 35-year-old female patient, who was evaluated previously at another hospital, because of recurrent episodes of pleurodynia, severe epigastric pain, vomiting and constipation during the last week is presented. The chest radiograph revealed a cyst which contains air in the left lower lung field. From her past medical history the patient reported a serious car-accident a year ago, for which she was admitted to ICU for two months. Laboratory testing revealed leukocytosis. An urgent CT scan of the chest and abdomen revealed a cyst in the left lower lobe of the lung containing a freely floating endocyst (the “water-lily sign”). This “water-lily” or “meniscus” sign denoting the entrance of air between the laminated membrane and the pericyst through a bronchopericystic fistula is observed as a thin, radiolucent crescent in the upper part of the cyst on plain radiography. The ultrasound examination revealed no evidence of rupture of the cavity within the abdomen or any hepatic involvement. Emergency gastroscopy followed, in which stomach contents were not allowed to complete the examination. The patient underwent emergency thoracic exploration. At operation we found that the cyst was a pseudo-cyst as it was a part of the stomach which had slid into the thorax. The fibrin-necrotic lesion of the left hemidiaphragm as a result of past accident of the patient gave to the upper part of the stomach the opportunity to escape from the abdomen into the thorax. This part was finally winding through fibrin lesions of hemidiaphragm, engulfed therein food and gastric juice and gave the described clinical picture.

Conclusions: This is a rare case of post-traumatic complication of the hemidiaphragm that resembles the water-lily sign, which is seen almost exclusively in hydatid infection, when there is detachment of the endocyst membrane which results in floating membranes within the pericyst that mimic the appearance of a water-lily.

Keywords: Bronchoscopy; water-lilli; cyst