The empty cyst sign is described in hydatid disease. After rupture of the cyst and complete evacuation of its content, the pericyst becomes empty as an air-filled cyst on x-ray or CT 1,2. With superadded infection, an air-fluid level may appear within the cyst, mimicking a lung abscess 2.
- 1. H A Pendse, A J Nawale, S S Deshpande, S A Merchant. Radiologic Features of Hydatid Disease. (2015) Journal of Ultrasound in Medicine. 34 (5): 895. doi:10.7863/ultra.34.5.895 - Pubmed
- 2. Garg MK, Sharma M, Gulati A, et al. Imaging in pulmonary hydatid cysts. (2016) World Journal of Radiology. 8 (6): 581. doi:10.4329/wjr.v8.i6.581 - Pubmed