Water Lily Sign: Typical of Ruptured Hydatid Cyst

Abstract

A 16-year-old girl presented to the casualty with fever, chills, cough with mucoid expectoration, breathlessness, and left-sided chest pain for two days. She had similar complaints, including several episodes of vomiting associated with nausea, anorexia, and generalised weakness over the past two weeks. The patient had a history of hospital admissions for similar complaints in the past that were not resolved with any medications. On examination, she was cachectic, afebrile, had a pulse rate of 96 per minute, and a blood pressure of 110/70 mmHg. On auscultation, there was reduced breath sounds on the left mammary region, with some fine crepitations heard in the left infrascapular region. A chest X-ray revealed a large thin-walled cavity with an irregular air-fluid level due to folded membranes, appearing as a water lily sign or camalote sign [Table/Fig-1]. A Computed Tomography (CT) of the thorax showed a large cyst measuring 9×9 cm in the left lung, with an air-fluid level and crumpled membranes lying inside the cyst in the dependent position [Table/Fig-2]. A blood sample was tested for Immunoglobulin G (IgG) antibodies against Echinococcus granulosus, which was positive (1.27). A diagnosis of a pulmonary ruptured hydatid cyst was made. The patient was started on oral albendazole 400 mg twice daily for 21 days. She responded well to medical treatment and was referred to a thoracic surgeon at a higher center for excision of the cyst and lobectomy.

Keywords

• camalote sign
• echinococcus granulosus
• pulmonary hydatid cyst