Ultrasound Finding: 

• On ultrasound, several patterns may occur, from a simple cyst to a complex mass with acoustic enhancement. 
• The shape may be oval or spherical, with regularity of the walls. Calcifications may occur. 
• Septations are very frequent and include honeycomb appearance with fluid collections; "water lily" sign, which shows a detachment and collapse of the germinal layer; or "cyst within a cyst."