Lymphatic Malformations

What is a lymphatic malformation?

A lymphatic malformation is a mass in the head or neck that results from an abnormal formation of lymphatic vessels. Lymphatic vessels are small canals that lie near blood vessels and help carry tissue fluids from within the body to the lymph nodes and back to the bloodstream.

There are 2 main types of lymphatic malformations:

  • Lymphangioma. A group of lymphatic vessels that form a mass or lump. A cavernous lymphangioma contains greatly enlarged lymphatic vessels.

  • Cystic hygroma. A large cyst or pocket of lymphatic fluid that results from blocked lymphatic vessels. A cystic hygroma may contain multiple cysts connected to each other by the lymphatic vessels.

Nearly all cystic hygromas happen in the neck. Some lymphangiomas can happen in the mouth, cheek, and tissues surrounding the ear, as well as other parts of the body. Lymphatic malformations are present at birth, but they are sometimes not found until the child is older. Some lymphatic malformations can spread into surrounding tissues and affect the proper development of the area. Lymphatic malformations may also enlarge and become infected following an upper respiratory infection.

Lymphatic malformations are sometimes seen in children with certain chromosome abnormalities and genetic conditions. These include Down syndrome and Turner syndrome.

What causes a lymphatic malformation?

A lymphatic malformation is a congenital (present from birth) defect that happens during early embryonic development when the lymphatic vessels do not properly form. The vessels may become blocked and enlarged as lymphatic fluid collects in the vessels. This forms a mass or a cyst.

What are the symptoms of a lymphatic malformation?

An internal lymphatic malformation in the mouth or cheek may not be noticed until it becomes infected and enlarges. Cystic hygromas can grow very large and may affect breathing and swallowing. The following are the most common symptoms of a lymphatic malformation. However, each child may experience symptoms differently. Symptoms may include:

  • A mass or lump in the mouth, cheek, or tongue beneath the mucous membrane that lines the area

  • A large, fluid-filled mass to the lower side and back of the neck under the platysma muscle. This is a thin, flat muscle extends from the upper chest to the jaw.

The symptoms of a lymphatic malformation may look like other neck masses or medical problems. Always talk with your child's health care provider for a diagnosis.

How is a lymphatic malformation diagnosed?

During pregnancy, a fetal ultrasound may find some large lymphatic malformations. Ultrasound is a diagnostic tool used to evaluate organs and structures inside the body with high-frequency sound waves. After birth, diagnosis of a lymphatic malformation is generally determined by a physical exam. In addition to a complete medical history and physical exam, diagnostic procedures for a lymphatic malformation may include the following:

  • Transillumination. A method of exam by the passage of light through tissues to assist in diagnosis. The light transmission changes with different tissues.

  • Computed tomography scan (also called a CT or CAT scan). A CT scan is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays and help to determine if other organs are connected to the malformation.

  • Magnetic resonance imaging (MRI). This can show better soft tissue characteristics and is sometimes helpful to distinguish what type of lymphatic malformation is present. 

Treatment of lymphatic malformation

Specific treatment of lymphatic malformation will be determined by your child's health care provider based on:

  • Your child's age, overall health, and medical history

  • Extent of the condition

  • Your child's tolerance for specific medicines, procedures, or therapies

  • Expectations for the course of the condition

  • Your opinion or preference

Treatment may include:

  • Observation of the malformation (to watch for growth or changes)

  • Antibiotic medicines (to treat infection)

  • Surgery (to remove the lymphatic malformation)

  • Sclerotherapy (to scar the sac so that it cannot fill again)

A small percentage of lymphangiomas can regrow and are often detectable within a year after surgery. Regrowth is more likely with larger and more complicated malformations.