Imagine discovering a mysterious swelling on your infant’s neck or a cluster of translucent blisters on their skin, harmless at first glance, yet persistent. These could be signs of Lymphangioma, a rare condition affecting the lymphatic system. Understanding the nature of this condition and early diagnosis can help prevent complications and guide appropriate treatment, especially when vital functions like breathing or swallowing are affected.

What is Lymphangioma?

Lymphangioma, also known as lymphatic malformation (LM), is a rare, benign (non-cancerous) condition resulting from abnormal lymphatic system growths. The lymphatic system is crucial in immune defence and fluid drainage throughout the body. When lymphatic vessels fail to form properly during fetal development, they form clusters of fluid-filled cysts or sponge-like structures under the skin or deeper within the body tissues.¹

While these malformations are benign, they can enlarge over time, especially during infections or trauma. Sometimes, they may press against nearby organs, blood vessels, or airways, causing discomfort or interfering with normal body functions.²

What causes LM?

Although the precise trigger is still under investigation, recent research^12,13,14 shows that many LM cases carry a non-inherited mutation in the PIK3CA gene. The gene typically helps regulate cell growth, but when mutated, it causes an overgrowth of lymphatic channels. When the mutation is accompanied by visible overgrowth, the term PROS (PIK3CA-Related Overgrowth Spectrum) is used.²

Who is affected?

LMs usually develop during pregnancy and are present at birth. While they are commonly diagnosed in infants and young children, they can occasionally appear later in life.

These malformations are more frequently observed in individuals with certain genetic conditions, including:¹

• Noonan syndrome
• Turner syndrome
• Down syndrome (Trisomy 21)
• Edwards syndrome (Trisomy 18)
• Patau syndrome (Trisomy 13)

These syndromes can affect how the body’s tissue and blood vessels form, increasing the risk of abnormal lymphatic development. For instance, Turner syndrome involves the absence or alteration of one X chromosome, which can disrupt normal vascular growth.³ Similarly, Noonan syndrome and trisomy conditions­ are linked to broader developmental differences that influence how lymphatic structures form and function.

Although LMs can affect people of any age or background, they are more commonly identified in those with these underlying syndromes due to their shared patterns in early development.⁴

Types of LM

LMs can vary in appearance, depth, and the symptoms they cause. Clinicians typically classify them into two main categories based on how deep they are in the body:^5,6

Superficial Lymphangioma (SL)

Found just beneath or on the skin surface, and tends to appear as clusters or tiny, clear or red vesicles. Although often small, they can cause cosmetic concerns, especially when located on visible areas such as the face or neck.

• Lymphangioma Circumscriptum: The most common type of SL, it presents as grouped, blister-like bumps that may resemble warts or small vesicles filled with clear fluid. They often occur on the upper arms, shoulders, neck, or inside the mouth
• Acquired Lymphangioma: Unlike most LMs, which are present from birth, this type develops later in life, often after trauma, surgery, or chronic inflammation that disrupts normal lymph flow. It usually affects adults and may resemble lymphangioma circumscriptum in appearance

Deep Lymphangioma (DL)

It grows deeper beneath the skin and can be more extensive; it often involves tissues like muscle or fat and is more likely to cause swelling, pressure symptoms, or disfigurement.

• Cavernous Lymphangioma: Consists of large, dilated lymphatic spaces, which usually appear as soft, poorly defined swellings and may not be readily noticeable at first. As they grow, they can cause compression of nearby structures
• Cystic Hygroma: A well-known and more dramatic form of DL, they are large, fluid-filled sac commonly found in the neck and lower face. Cystic hygromas can grow rapidly and interfere with breathing, feeding, or speech, particularly in infants. They are often diagnosed before birth or shortly afterwards

Signs & symptoms

Symptoms of LMs can vary widely depending on the type, size, depth, and location. Some may be noticeable at birth, while others become noticeable during childhood as they grow.

General features

• Soft, spongy, or cystic lump under the skin
• Skin over the area may appear skin-coloured, reddish-blue, or even translucent if close to the surface
• Sizes can range from tiny blisters to large masses
• Usually painless, but may become tender and swollen due to infection or trauma⁷

While all LMs share some common characteristics, the symptoms can vary significantly based on the specific type:^1,6

Lymphangioma Circumscriptum

• Found on shoulders, neck, arms, legs, mouth, or armpits
• Appears as clusters of small blisters that resemble frogspawn
• Clear, red, pink, brown, or black in colour
• Can ooze, bleed, or become warty, especially if located on hands or feet
• May become more noticeable during puberty

Cavernous Lymphangioma

• Often located on the tongue, but can develop anywhere
• Appear as rubbery, painless swelling under the skin
• Red, blue or skin-coloured in colour
• Usually diagnosed with ultrasound, showing fluid-filled spaces

Cystic Hygroma

• Commonly found on the neck, armpits, or groin, may extend to the chin, face, or chest
• Appears as a significant swelling
• Usually translucent but may be red, blue, or skin-coloured
• Can interfere with breathing or swallowing in severe cases
• It may become life-threatening if it grows rapidly or becomes infected
• Often diagnosed by ultrasound or MRI
• May be associated with developmental genetic conditions

How is LM diagnosed?

LMs are typically identified by a combination of clinical examination and imaging:^9,10,11

Prenatal

Large LMs, especially cystic hygromas, which manifest as fluid-filled sacs in the developing fetus, can be found with a routine prenatal ultrasound scan. If detected, further monitoring and genetic testing may be recommended to guide diagnosis and inform the development of an appropriate treatment plan.

Postnatal

Most LMs are diagnosed during infancy or early childhood, with approximately 80% of cases identified before the age of two,⁸ often when a parent or clinician notices a lump or swelling. These growths are usually soft, compressible, and may feel spongy or rubbery to the touch.

Imaging

Clinicians recommend the following to gain a better understanding of the size, depth, and potential impacts of LMs:

• Ultrasound: The first choice, it helps determine if the swelling is cystic and fluid-filled
• MRI: Provides detailed images of soft tissues and helps evaluate the lesion’s depth
• CT: Used for deeper or more complex lesions, particularly those affecting the abdomen or chest

Other

• Biopsy: To rule out other skin disorders, a tissue sample may be taken if the diagnosis is uncertain
• Dermoscopy, a magnified skin exam, may be used to examine SLs more closely. Although this is more common in a dermatology setting, and is not always needed⁵

Management & treatment

LMs don’t always require treatment. However, medical intervention may be needed if they cause discomfort, interfere with normal functions, grow rapidly, or become infected.^2,8,10

Surgery

Surgical removal is often used when the lesion is well-defined and accessible. It is most effective for small or superficial LMs. However, deeper LMs can be challenging to remove completely, especially if they are close to nerves or blood vessels. In such cases, surgery may be avoided unless necessary. Risks include scarring and nerve damage, particularly for lesions near sensitive areas such as the face or neck.

Sclerotherapy

A less invasive alternative to surgery, it involves injecting a sclerosing agent into the cyst to shrink it. Sclerotherapy is particularly effective for larger, fluid-filled LMs and carries a lower risk of damaging surrounding tissues. It is commonly used for bigger or deeper LMs.

Laser therapy

CO₂ laser and Nd: YAG laser therapies are options for superficial laser moles (Superficial LMs). These lasers can remove or flatten visible lesions, improving cosmetic appearance and reducing symptoms such as bleeding or oozing.

Treatment decisions depend on factors like the LM’s size, location, depth, symptoms, and potential complications. In some mild or asymptomatic cases, especially for superficial LMs, a “watch and wait” approach may be adopted. Newer therapies such as radio frequency ablation (RFA), which uses heat generated by radio waves to destroy lesions, are also being explored as alternatives when traditional approaches aren’t feasible.

FAQs

Can LM be prevented?

No, they are caused by the abnormal development of the lymphatic system during pregnancy. However, if your child has a known genetic condition like Down syndrome or Turner syndrome, early monitoring may help detect issues sooner. Genetic counselling may be helpful for individuals planning on conceiving and who have concerns.

Will it come back after treatment?

Unfortunately, LMs tend to recur, especially if they aren’t fully removed or treated. It is more likely to occur in deep or widespread lesions, but with combination therapies and effective care, symptoms can be kept under control.

Is LM hereditary?

No. While some forms may be associated with genetic syndromes, the majority are a result of developmental anomalies in the womb.

Will LM affect my child’s development or growth?

Most LM don’t directly impact overall growth. However, if they press on structures, like the food pipe, airways, or joints, interfering with vital functions, early treatment and monitoring help minimise the risks.

Summary

Lymphangioma, also known as lymphatic malformation (LM), is a rare but benign condition that can present as small clusters, blisters, or large fluid-filled masses. While most cases are present at birth and don’t cause serious problems, some may grow over time, causing cosmetic concerns or interfering with vital functions such as breathing or swallowing.

With early diagnosis and appropriate care, ranging from observation to surgery or sclerotherapy, most people with LM can manage their condition effectively and lead healthy lives.