Fetal Treatment Program of New England

Lymphatic and Vascular Malformations

Vascular malformations are congenital lesions of the capillaries, veins, lymphatic vessels and/or arteries, caused by abnormal cell growth. Though present at birth, vascular malformations may not become visible for weeks or months. If left untreated, a malformation will continue to grow, usually in proportion to the growth of the child. Treatment is specific to the type of malformation, but generally involves removal through a procedure after birth.

One of the most common types is the lymphatic malformation, in which fluid collects in the lymphatic vessels and forms a benign mass or cyst, usually in the head and neck region. The malformation may enlarge and become infected, which can cause breathing problems and/or hinder the development of surrounding tissue. They are sometimes seen in babies with chromosomal defects or other genetic conditions.

How are they diagnosed? 

Lymphatic malformations are sometimes detected through routine ultrasound; however, more often they are diagnosed after birth until the age of two years through physical examination. If detected prenatally, observation is needed throughout the remained of the pregnancy. Level II ultrasound and fetal MRI are used to determine the size and development of the lymphatic malformation, and to assess the potential for airway obstruction.

What can happen before birth? 

Usually lymphatic malformations do not cause harm to the growing fetus. Occasionally, the growth of the malformation and collection of the fluid may occur in the fetal chest or abdomen, causing strain on the growing fetal heart.

What can be done before birth? 

Lymphatic malformations are usually not treated with fetal intervention unless there is evidence of hydrops, where there is too much fluid in the chest that can be relieved by aspirating or draining the lymphatic fluid.

What are my delivery options? 

Unless there are signs that the fetus is in trouble, pre-term delivery or Cesarean section is not necessary. Cesarean section may be necessary for obstetrical reasons, however.

What will happen at birth? 

In rare cases when the airway is affected, an EXIT procedure is required at delivery.

After birth, babies with lymphatic malformations typically undergo imaging (chest x-ray, ultrasound and/or MRI) to assess the structure and severity of the malformation. Treatment depends on several factors, including the baby's overall health and the severity of the malformation. Smaller malformations sometimes may be removed surgically with excellent results, while larger ones may require sclerotherapy, in which medicine to shrink the defect is delivered through a catheter and needle. Lymphatic malformations can become infected and require antibiotics.

What is the long-term outcome? 

Multiple sclerotherapy procedures are sometimes needed; however, lymphatic malformations can be treated with good to excellent results in more than 50% of cases.