Cystic hygroma is a fluid-filled sac that usually occurs in the neck or head area, often present at birth. It results from a blockage in the lymphatic system, which is responsible for draining excess fluid from tissues. This condition can vary in size and may be detected through imaging tests like ultrasound during pregnancy or after birth. While cystic hygromas are generally benign, they can sometimes lead to complications, such as difficulty breathing or swallowing. Treatment options may include surgical removal, especially if the hygroma is large or causing problems. Early diagnosis and management are important for better outcomes.