Lymphangioma, also known as lymphatic malformation, is a rare noncancerous condition where fluid-filled cysts develop under the skin, most commonly appearing on the head or neck of newborns and young children. These growths form when lymph fluid backs up in the lymphatic system during development, creating masses that can range from tiny bumps to large swellings. While most cases don’t cause serious health problems, understanding this condition helps families navigate the diagnosis and make informed decisions about care.

How Common is Lymphangioma?

Lymphangioma is considered a rare condition that affects approximately 1 in 4,000 to 1 in 6,000 newborns worldwide. This means that while it’s not something every parent will encounter, it’s not extremely unusual either^[1][3]. The condition doesn’t show any preference for gender or race, affecting boys and girls equally across all ethnic backgrounds^[3].

The timing of when lymphangiomas become noticeable is quite specific. Most of these malformations are present at birth or become apparent very early in life. About half of all lymphangiomas that develop on the head or neck are recognized immediately at birth, and approximately 90 percent will be visible by the time a child reaches their second birthday^[12]. In rare cases, smaller lymphangiomas may go unnoticed during infancy and only become apparent during the teenage years or even early adulthood, particularly if they’re located inside the body where they’re harder to see^[6].

The location of lymphangiomas follows a distinct pattern. About 75 percent of these malformations occur in areas rich with lymphatic vessels, particularly the head and neck region^[6][12]. However, they can develop anywhere on the body, including the armpits, chest, arms, legs, and even internal organs. This wide distribution means that each case can look quite different depending on where the malformation forms.

What Causes Lymphangioma?

The exact cause of lymphangiomas remains unknown to scientists, but they have a good understanding of when and how these malformations develop. Lymphangiomas form during fetal development when the lymphatic system — the network of vessels that carry lymph fluid throughout the body — doesn’t develop properly^[1][8]. This is not something caused by anything a mother did or didn’t do during pregnancy. No food, medication, or activity during pregnancy can cause a lymphatic malformation^[7].

During normal development, the lymphatic system forms a complex network of channels that drain fluid from tissues and return it to the bloodstream. When something goes wrong during this process, the lymphatic vessels may not connect properly to the main drainage system. This blockage or disconnection causes lymph fluid to back up and pool, creating the fluid-filled cysts that characterize lymphangiomas^[9].

Lymphangiomas are described as a “somatic mutation,” which means that while they affect the genes, they are not inherited conditions passed from parents to children^[3]. This is an important distinction because it means that parents who have a child with a lymphangioma are not necessarily at increased risk of having another child with the same condition. The genetic changes that lead to lymphangiomas happen spontaneously during development rather than being inherited through family genes.

Recent research has identified that approximately 75 to 80 percent of lymphatic malformations are caused by specific mutations in a gene called PIK3CA^[6]. This discovery has helped scientists better understand how these malformations form, though it hasn’t yet led to ways to prevent them.

Risk Factors for Developing Lymphangioma

While lymphangiomas can occur in any child, certain factors appear to increase the likelihood of developing these malformations. Understanding these risk factors can help families and healthcare providers be more alert to the possibility of lymphangiomas, particularly before birth when some can be detected through ultrasound.

One of the most significant risk factors is the presence of certain chromosomal disorders — conditions where a person has too many or too few chromosomes. About half of all babies born with macrocystic lymphatic malformations, which are the large, deep cysts often called cystic hygromas, also have a chromosomal disorder^[1][8]. The most common associated conditions include Down syndrome, Turner syndrome, and Noonan syndrome^[1][3].

Down syndrome, which involves an extra copy of chromosome 21, is one condition where lymphangiomas appear more frequently. Turner syndrome affects girls and involves missing or incomplete X chromosomes. Noonan syndrome is a genetic disorder that affects multiple body systems and can be inherited or occur spontaneously. Children with any of these conditions should be carefully monitored for signs of lymphatic malformations.

In some cases, lymphangiomas occur alongside other congenital malformations, meaning birth defects that are present from birth. These can include heart defects or skeletal abnormalities^[21]. When lymphangiomas appear as part of a broader pattern of birth differences, doctors will typically conduct additional testing to understand the full picture of a child’s health needs.

A family history of lymphatic malformations may slightly increase the risk, though this is not common since most cases occur spontaneously^[21]. Unlike many inherited conditions, having a family member with a lymphangioma doesn’t guarantee that other family members will develop the condition.

Recognizing the Symptoms

The appearance and symptoms of lymphangiomas vary considerably depending on their size, location, and type. Most importantly, these malformations typically don’t cause pain and shouldn’t be itchy^[1][8]. This can be reassuring for families, as it means the condition itself isn’t causing discomfort to the child, though complications can occasionally arise.

The most obvious sign of a lymphangioma is swelling or a visible mass under the skin. These growths can appear as tiny bumps no bigger than a few millimeters, or they can develop into large masses that cause significant deformity^[1][8]. The appearance depends on which type of lymphatic malformation is present.

Macrocystic lymphatic malformations, also called cystic hygromas, are large, soft masses that feel spongy when touched. They most often appear deep within the neck, face, armpits, or chest. The skin over these masses may look reddish-blue in color^[1][8]. These larger malformations can grow quite large and may be noticed during pregnancy through prenatal ultrasound, or they may be obvious immediately at birth.

Microcystic lymphatic malformations, sometimes called lymphangioma circumscriptum, consist of smaller, pimple-sized cysts that appear closer to the surface of the skin. These typically show up on the arms, legs, chest, armpits, and mouth. The color can vary considerably, ranging from clear to pink to black, especially if bleeding occurs into the cysts^[1][8]. These smaller vesicles may look like tiny blisters or bubbles on the skin surface^[22].

Some children have mixed lymphatic malformations, which combine features of both the large and small types^[1][8]. This means they may have both deep, large cysts and superficial, smaller ones in the same area.

While most lymphangiomas are localized to one area of the body, occasionally they can be widespread. When lymphatic malformations occur throughout the bones and soft tissues, the condition is called lymphangiomatosis^[1][8]. This more extensive involvement is rare but requires more comprehensive medical management.

Symptoms become more serious when lymphangiomas affect internal structures or vital organs. When they develop in the bones, they may cause bone loss or abnormal bone growth^[1][8]. Lymphangiomas in the chest can cause chest pain, shortness of breath (called dyspnea), or wheezing. Those affecting the eyes may cause bulging eyes or double vision. Malformations in the mouth or windpipe can lead to feeding difficulties, speech problems, or trouble swallowing^[1][8].

One of the more serious complications occurs when large lymphangiomas in the neck grow large enough to press on the airway, potentially causing breathing difficulties^[1][8][3]. This situation requires immediate medical attention and may need treatment to ensure the child can breathe properly.

Infection represents another potential complication. When lymphangiomas become infected, the area may become painful, red, warm, and swollen. This is called cellulitis, and it requires treatment with antibiotics^[3][10]. The superficial vesicles can rupture or be injured, releasing clear or blood-tinged fluid and creating an entry point for bacteria.

Prevention Strategies

Unfortunately, there are currently no known ways to prevent lymphangiomas from developing. Because these malformations result from spontaneous developmental errors that occur during fetal growth, they cannot be prevented through lifestyle changes, medications, or other interventions before or during pregnancy^[1][8].

Since lymphangiomas can sometimes be associated with chromosomal disorders like Down syndrome, Turner syndrome, or Noonan syndrome, prenatal genetic testing may help identify pregnancies where there’s an increased risk of lymphatic malformations. Fetal ultrasounds performed during routine prenatal care can sometimes detect larger lymphangiomas, particularly cystic hygromas in the neck area^[7]. Early detection allows families and healthcare teams to prepare for any care the baby might need after birth.

For children who already have lymphangiomas, prevention focuses on avoiding complications rather than preventing the initial malformation. Maintaining good overall health and hygiene helps prevent infections in areas affected by lymphangiomas^[21]. Parents should be taught to watch for signs of infection, such as increased redness, warmth, pain, or fever, and to seek medical care promptly if these occur.

Avoiding trauma or injury to areas with lymphangiomas is also important. The malformations contain fragile blood vessels that can bleed easily, even with minor injuries^[22]. Teaching children to be careful with affected areas and protecting them during sports or active play can help reduce the risk of bleeding or other complications.

How Lymphangioma Affects the Body

To understand how lymphangiomas affect the body, it helps to first understand the normal function of the lymphatic system. This system consists of a network of vessels, tissues, and organs that work together to move lymph — a colorless fluid containing white blood cells called lymphocytes — throughout the body^[1][8]. The lymphatic system plays important roles in maintaining fluid balance in tissues, absorbing fats from the digestive system, and supporting immune function.

In normal circumstances, lymph fluid is continuously produced in tissues throughout the body. This fluid is collected by tiny lymphatic vessels and eventually returned to the bloodstream through larger lymphatic channels. The system includes lymph nodes positioned at intervals along these vessels, which help filter the lymph and remove harmful substances like bacteria and cancer cells^[3].

In lymphangiomas, the normal flow and drainage of lymph is disrupted. During fetal development, some lymphatic vessels fail to connect properly to the main lymphatic drainage system. Instead of draining normally, these isolated vessels become blocked or disconnected^[9][18]. When lymph fluid continues to be produced but cannot drain away, it accumulates in these abnormal vessels, causing them to swell and form cysts.

The walls of these malformed lymphatic vessels are often fragile and contain abnormally formed blood vessels. This makes them prone to bleeding, which can occur spontaneously or with even minor trauma^[22]. When bleeding occurs into a lymphangioma, the cyst fills with blood in addition to lymph fluid, which can cause it to grow larger and change color, often appearing dark red or purple.

As lymphangiomas grow, they can create pressure on surrounding structures. The extent of this pressure depends on the size and location of the malformation. Small, superficial lymphangiomas may cause no functional problems at all, simply appearing as bumps on the skin. However, larger or deeper malformations can compress nearby organs, blood vessels, nerves, or airways, leading to various symptoms and complications^[1][8].

In some cases, particularly with macrocystic lymphangiomas, the malformation can grow to a significant size. The pooling lymph and blood stretches the vessels and cysts, making the lymphangioma expand over time^[22]. This growth may be gradual, occurring as the child grows, or it may happen more rapidly during periods called “flares” when extra fluid accumulates or bleeding occurs.

When lymphangiomas affect bones, they can interfere with normal bone development and remodeling. This may result in either bone loss or abnormal bone overgrowth in the affected area^[1][8]. If lymphangiomas involve joints or limbs, they can cause those body parts to grow larger than their counterparts on the other side of the body, leading to asymmetry.

The immune system may respond to lymphangiomas as well, particularly if they become infected. The stagnant lymph fluid in malformed vessels doesn’t circulate normally, which means it doesn’t benefit from the usual immune surveillance that occurs in healthy lymphatic tissue. This can make lymphangiomas more susceptible to bacterial infections, which then trigger inflammation and pain^[3].

Despite these various effects, it’s important to emphasize that lymphangiomas are not cancerous. The cells that make up these malformations are benign and do not have the ability to spread to other parts of the body or invade surrounding tissues in the way cancer does^[1][8]. They represent developmental errors rather than abnormal cell growth, which is why the medical community has largely moved away from older terms like “lymphangioma” (which suggests a tumor) in favor of “lymphatic malformation” (which more accurately describes a structural problem)

^[6].