What is the waterlily sign ?

The waterlily sign (Fig. 1) represents the freely floating endocyst of the Echinococcus granulosus, causing hydatid cysts (HC). The HC is severe, neglected, misdiagnosed, worldwide infectious disease, caused by a tapeworm, Echinoccocus granulosus, endemic of rural areas. Humans are incidental hosts. Fever and constitutional symptoms usually occur only if there is rupture or bacterial superinfection of the cyst. Ultrasound remains the diagnostic method of choice in the work-up of hepatic cystic lesions; it can differentiate cystic echinococcosis from the alveolar form, caused by Echinoccocus granulosus (Fig. 2) and Echinoccocus multilocularis, respectively. The current standard of treatment is based on the WHO Classification; Albendazol is the drug of choice; according to the clinical scenariO. Puncture, Aspiration, Injection, and Reaspiration (PAIR) and surgery are correctly indicated. The rate of cyst recurrence is 16.2% , 3.3% and 3.3% with open surgery, percutaneous intervention and laparoscopic surgery, respectively.