To understand lymphatic malformation, it's important to understand a bit about the lymphatic system.

• Lymphatic vessels are like blood vessels. The difference is they carry a clear fluid instead of blood.
• The lymphatic system collects extra fluid from the tissues of the body and carries it back to the veins.
• If the system is not formed normally, the fluid is slow to travel back to the veins and extra fluid collects in the body. This leads to swollen or enlarged soft tissues and bones. This is called a lymphatic malformation.
• Lymphatic malformation is caused by defective lymphatic vessel development before birth, probably due to a localized genetic mutation. They are present at birth but may not show up until later.
• A lymphatic malformation can be composed of a collection of cysts or enlarged channels or vessels. It can be localized or very extensive, affecting multiple parts of the body.
• A lymphatic malformation is sometimes seen in children who have other genetic conditions.

If the lymphatic system is not formed normally, the fluid is slow to travel back to the veins and extra fluid collects in the body. This leads to swollen or enlarged soft tissues and bones that is called a lymphatic malformation.

The malformation may stop growing, but some will keep growing and may grow quickly during puberty. Larger malformations may get infected, bleed or cause injury to the surrounding area.

They are most often seen in the neck and armpit, but they can be in any part of the body. The changes can be seen in the skin or deep in the body's tissues. In the skin, they appear like bubbles that can be clear, red or black. Under the skin, they cause swelling and tissue enlargement.

Superficial lymphatic malformation

Lymphatic malformation is visible as abnormal collections of fluid on imaging studies such as ultrasound, CT or MRI. An ultrasound done before birth may show some of the larger malformations in the fetus of a pregnant woman. After a baby is born, these larger malformations can be felt or seen during a physical exam.

• MRI: A MRI scanner uses a large magnet, radio waves and a computer to take pictures of parts inside the body. It does not use radiation. It is the best test to show the full extent of abnormality.
• Ultrasound: An ultrasound is not an X-ray, it works by using sound waves to make images of body parts. Your child will not hear or feel the sound waves.

Deep malformation

Treatments for malformations vary. They may include:

• Watching for any further growth
• Antibiotic medicine to treat infection
• Image-guided treatment. Sclerosing medications such as doxycycline or picibanil are injected into the cysts in the Interventional Radiology suite. The injection damages the cyst walls causing them to collapse and become replaced by scar tissue. The injections [sclerotherapy] may need to be repeated.
• Surgery to remove all or part of the malformation. A lymphatic malformation may grow back if it cannot be removed completely.

Even with treatment, a lymphatic malformation may grow back. This tends to happen with larger malformations.

Other Helpful Resources for Families:

• Mulliken JB, Burrows PE and Fishman SF. Mulliken and Young's Vascular Anomalies. Hemangiomas and Malformations second edition. Oxford University press 2013
• Blei F, Anglin C. 100 Questions and Answers about Vascular Anomalies. Jones and Bartlett publishers 2011

Alert

Call your child's doctor, nurse, or clinic if you have any concerns or if your child has:

• Sudden swelling or fever
• An infection that will not heal
• Bleeding that will not stop
• Special health care needs not covered by this information