Symptoms of a cystic hygroma vary based on the size and location of the fluid-filled sac (cyst). Symptoms could include: A bulge under the skin. Skin over the cyst has a blue tint. The cyst is soft. The cyst most often appears on the neck, but it can form anywhere on the body. Size ranges from a grape to grapefruit and could increase in size as the baby grows. Severe symptoms of a cystic hygroma include: Physically disfigure part of the body. Bone or organ damage. Feeding difficulties. Difficulty breathing (airway obstruction). Hemorrhage. Infection.