A cystic hygroma is a fluid-filled sac that usually forms in the neck or head area, often seen in newborns. It results from a blockage in the lymphatic system, which is responsible for draining excess fluid from tissues. These growths can vary in size and may be detected during pregnancy through ultrasound. Cystic hygromas can sometimes be associated with genetic conditions, such as Turner syndrome or Down syndrome. Treatment options may include surgical removal, especially if the hygroma is large or causing complications. Early diagnosis and management are important for better outcomes.