Infected Primary Paraspinal Hydatidosis with Water Lily Sign

Abstract Background Primary muscular hydatidosis is extremely rare, and the diagnosis of the infected muscular hydatid cyst can be difficult due to atypical clinical and radiological findings. Case Report We present herein an interesting case of a 24-year-old man with primary infected muscular hydatid cyst located in the paraspinal muscles eroding the right lamina of C6 vertebra that was diagnosed with water lily sign on computed tomography. Conclusion Water lily sign is a pathognomonic imaging finding for hydatidosis, and defined when free-floating endocyst is seen. Cyst hydatid should always be considered in the differential diagnosis of any soft tissue mass of the patients from endemic regions.