What Is a Lymphangioma? Types, Symptoms, and Treatment

A lymphangioma is a fluid-filled growth that forms when lymphatic vessels develop abnormally, creating clusters of cysts or channels instead of the normal drainage network. These growths are benign, meaning they do not spread to distant parts of the body the way cancer does, but they can cause serious problems depending on where they appear and how large they become. Most are present at birth or show up in early childhood, and they arise from somatic mutations in genes that regulate cell growth rather than from anything a parent did during pregnancy.

How Lymphangiomas Form

The lymphatic system is a network of thin-walled vessels that carries fluid, immune cells, and waste products throughout the body. When something goes wrong during the development of these vessels, pockets of lymphatic tissue can balloon out and fill with fluid. The result is a lymphangioma, more precisely called a lymphatic malformation in current medical terminology.

The underlying cause in most cases is a somatic mutation, meaning a genetic change that happens randomly in a cell during fetal development rather than being inherited from a parent. These mutations tend to occur in genes that are part of growth-signaling pathways the body normally uses to regulate cell division. When one of these genes gets stuck in an “on” position in lymphatic tissue, the vessels grow in a disordered way and form fluid-filled cavities.¹ Because the mutation is somatic, it only affects the cells that descend from that original mutated cell, which is why lymphangiomas tend to be localized to one area of the body rather than appearing everywhere at once.

Types of Lymphatic Malformations

The most practical way to think about lymphangiomas is by cyst size, because the size of the internal cysts largely determines symptoms, appearance, and how well different treatments work.

Macrocystic: These contain cysts larger than about 2 centimeters. They tend to form soft, compressible masses that are easy to see on imaging and often respond well to injection-based treatments like sclerotherapy.
Microcystic: These are made up of tiny cysts under 2 centimeters, often much smaller. They tend to infiltrate surrounding tissue rather than sitting in a neat package, and they frequently involve the skin surface. Microcystic lesions carry a higher risk of fluid leaking through the skin and infection, and they are harder to treat with sclerotherapy.
Mixed: Many lymphangiomas contain both large and small cysts. Treatment planning often needs to address each component differently.

Beyond these common localized forms, there is a spectrum of rarer, more widespread conditions sometimes called complex lymphatic anomalies, where abnormal lymphatic tissue affects multiple body regions or organs.² The distinction between macrocystic and microcystic matters practically because macrocystic lesions present as compressible masses that can be measured on imaging and respond well to sclerotherapy, while microcystic lesions are infiltrative, often cutaneous, and show a poorer response to sclerotherapy.³

Where They Appear and What They Feel Like

Lymphangiomas can technically develop anywhere the body has lymphatic tissue, but certain locations are far more common than others. The head and neck region is the classic site, especially in infants. A large neck lymphangioma, historically called a cystic hygroma, may be visible as a soft bulge under the skin. These masses tend to transilluminate, meaning they glow when a light is held against them, because they are filled with clear or straw-colored fluid rather than solid tissue.

The main danger with head and neck lesions is compression of the airway. A lymphangioma that wraps around the throat or pushes into the floor of the mouth can make breathing difficult, particularly in a newborn whose airway is already small. Rapid growth, bleeding into the cyst, or infection can all cause a previously stable lesion to swell suddenly.⁴ Cervical lymphangiomas that extend into the chest can be especially challenging because they may compress both the airway and the esophagus.⁵

Lymphangiomas also appear in the abdomen, though less frequently. Abdominal lymphangiomas often grow silently for years and may be discovered incidentally during imaging for another issue. When they do cause symptoms, it is usually vague abdominal discomfort or a palpable mass. Mesenteric lymphangiomas, which grow in the tissue that anchors the intestines, can occasionally cause bowel obstruction. One reported case involved a cystic lymph-filled mass roughly 12 centimeters across found in the mesentery of a 42-year-old woman.⁶

Superficial lymphangiomas that sit at or just beneath the skin surface often look like clusters of small, clear or reddish blisters. This presentation, sometimes called lymphangioma circumscriptum, can weep lymph fluid through the skin and is prone to recurrent infections. In the mouth, lymphangiomas may involve the tongue, gums, or floor of the mouth and can be confused with other cystic lesions like ranulas or branchial cysts on imaging.⁷

How Lymphangiomas Are Diagnosed

Diagnosis usually starts with clinical examination, but imaging is essential to understand the full extent of the lesion before any treatment. Ultrasound is typically the first step, particularly in children, because it is quick, painless, and does not involve radiation. It can reveal the cystic nature of the mass and help distinguish lymphangiomas from solid tumors.

MRI is the gold standard for mapping the malformation in detail. In a study of 17 lymphangiomas in children, MRI showed a characteristic appearance: most lesions appeared dark on one type of image sequence and very bright on another, reflecting their fluid content. Visible internal walls separating cyst chambers were present in nearly all cases. Some lesions appeared brighter than expected on certain sequences, reflecting the presence of blood or a higher fat-to-fluid ratio inside the cysts.⁸ This level of anatomic detail helps surgeons and interventional radiologists plan the safest approach.

When the diagnosis is uncertain under the microscope, pathologists can use specialized staining. A marker called D2-40 highlights the lining of lymphatic vessels specifically, helping to distinguish lymphangiomas from blood vessel growths that can look similar on standard staining.⁹

Treatment by Sclerotherapy

Sclerotherapy involves injecting a chemical agent directly into the cysts to damage the lining cells, causing the walls to stick together and the cyst to shrink. It has become the preferred first-line treatment for macrocystic lymphangiomas, partly because it avoids the nerve and vessel injury that can come with surgery in tight anatomic spaces like the neck.¹⁰

Several sclerosing agents are used. Bleomycin, an antibiotic with tissue-damaging properties, is one of the most widely studied. In a series of patients with massive macrocystic lesions treated with bleomycin injections, most responded favorably within one to four sessions, and major complications were absent. A small number needed additional sessions or surgical backup.¹¹

Doxycycline is another commonly used sclerosant. A newer technique called serial doxycycline exchange allows the drug to dwell inside the cysts over multiple sessions through a single catheter placement, reducing the number of separate procedures a patient needs. In a study of 44 patients treated this way, about 9 percent achieved full clinical remission, roughly 61 percent had improved symptoms, and about 30 percent saw no change or worsening. Median cyst volume shrank by more than 60 percent after one round of treatment.¹²

Sclerotherapy generally works best on macrocystic disease. Microcystic lymphangiomas, with their tiny, infiltrative cysts, are much harder to target with a needle. Treatment success for microcystic lesions is measured more by symptom relief than by imaging shrinkage, since the lesions are difficult to measure on scans.

When Surgery Is Needed

Complete surgical removal is the most definitive treatment, but it is not always practical. Lymphangiomas do not respect tissue planes the way a benign capsule-enclosed tumor does. They tend to wrap around nerves, blood vessels, and other structures, making total excision risky, especially in the neck, face, or chest. Incomplete removal frequently leads to regrowth.

Surgery is most straightforward when the lesion is well-defined and in an accessible location, such as a single macrocystic mass in the trunk or limb. For abdominal lymphangiomas growing in the mesentery, surgical excision with or without a segment of bowel is often the primary treatment, since sclerotherapy in the abdomen carries its own risks. In rare locations like the mediastinum (the central chest compartment), the patient’s overall condition may make surgery too dangerous, and alternatives like percutaneous drainage with injection of sealing agents have been used as a less invasive option.¹³

In practice, many patients end up with a combination approach: sclerotherapy to shrink the bulk of the lesion first, followed by surgery to remove residual tissue, or surgery upfront with sclerotherapy later for areas that were too risky to excise.

Medical Therapy With Sirolimus

One of the more exciting developments in lymphangioma treatment over the past decade is the use of sirolimus, a drug originally developed to prevent organ transplant rejection. Sirolimus works by blocking a signaling pathway that happens to be the same one activated by the somatic mutations behind many lymphatic malformations. When the pathway is dialed back, the abnormal lymphatic tissue can stop growing and even shrink.

A systematic review covering 52 patients treated with either oral or topical sirolimus for microcystic lymphatic malformations found clinically meaningful improvement lasting up to three years in 92 percent of cases. Improvements included reduced fluid leaking through the skin, less bleeding, smaller vesicle bulk, less pain, and fading of skin discoloration. Some patients noticed effects within two weeks. No unexpected side effects were reported.¹⁴

Topical sirolimus, applied directly to the skin over a superficial lesion, avoids the systemic side effects that oral dosing can bring, such as mouth sores, elevated blood lipids, and immune suppression. In one reported case, an eight-year-old girl with a microcystic lesion on her trunk that had recurred after surgery was treated with twice-daily topical sirolimus. After three months the lesions had nearly cleared, and no new lesions appeared over the following eight months of follow-up.¹⁵ Sirolimus has been a particular game-changer for microcystic disease, which historically had few good treatment options.

Laser Treatment for Superficial Lesions

When lymphangioma vesicles sit right at the skin surface, lasers can destroy them layer by layer. Fractional carbon dioxide laser ablation has been reported as a well-tolerated option with minimal downtime for palliation of symptoms in patients with superficial microcystic disease.¹⁶ The word “palliation” is important here: laser treatment reduces symptoms like oozing and bleeding from the skin surface, but it does not reach deeper components of the malformation, so regrowth of surface vesicles is common over time. Laser is best thought of as a maintenance tool rather than a cure, often combined with medical or injection-based therapies for deeper components.

Complications Worth Knowing About

Lymphangiomas are benign, but “benign” does not mean trouble-free. The most common complications include infection, bleeding into the cysts, and recurrence after treatment.

Infection is a recurring issue, particularly for superficial microcystic lesions. The thin vesicles at the skin surface provide an easy entry point for bacteria, and once the lymphatic fluid inside a cyst gets infected, the entire lesion can swell rapidly and become painful. Cellulitis episodes may require antibiotics and sometimes hospitalization. Families of children with superficial lymphangiomas are often taught to watch for sudden redness, warmth, and swelling as early signs of infection.

Intralesional hemorrhage, meaning bleeding inside the cyst chambers, can happen spontaneously or after minor trauma. When blood mixes with lymphatic fluid, a previously soft, skin-colored mass may turn blue or purple and enlarge quickly. Lymphangiomas with hemorrhage tend to cause more pain than those without, and sclerotherapy for hemorrhagic lesions typically requires more treatment sessions to achieve the same result as non-hemorrhagic ones.¹⁷ In rare abdominal cases, massive hemorrhage within a lymphatic malformation can mimic a surgical emergency.¹⁸

Prenatal Detection and Delivery Planning

Large lymphangiomas in the head and neck region are sometimes detected on routine prenatal ultrasound, often in the second trimester. When a fetal lymphangioma is large enough to potentially block the airway at birth, the delivery itself has to be carefully choreographed. A procedure known as EXIT (ex utero intrapartum treatment) allows the surgical team to secure the baby’s airway while the infant is still partially delivered and connected to the placenta for oxygen. This buys time to intubate or place a surgical airway before the umbilical cord is cut.¹⁹

In one reported case, a prenatal ultrasound revealed a rapidly growing cystic hygroma measuring roughly 20 by 10 by 18 centimeters that wrapped around the baby’s airway and extended into the chest and lower abdomen. Fetal MRI confirmed the mass was displacing the mouth, nose, and nasal cavity. The team planned an EXIT procedure to manage the anticipated severe airway compromise at delivery.²⁰ These cases illustrate why prenatal imaging matters so much: the difference between a planned EXIT delivery and an emergency cesarean with no airway plan can be lifesaving.

Acquired Lymphangiomas in Adults

While most lymphangiomas are congenital, a small number develop later in life as a consequence of damage to the lymphatic system. The best-documented example is lymphangioma appearing on the chest wall after radiation therapy for breast cancer. The radiation damages local lymphatic channels, leading to lymphatic obstruction and the eventual appearance of small, clear vesicles on the irradiated skin.²¹ These acquired lesions are typically superficial and asymptomatic at first, though they can become cosmetically bothersome or weep fluid over time. Other forms of lymphatic damage, including surgery that removes lymph nodes or chronic infections that scar lymphatic tissue, can sometimes produce similar secondary lymphangiomas.

The Link to Klippel-Trenaunay Syndrome

Lymphatic malformations sometimes appear as part of a broader syndrome rather than in isolation. Klippel-Trenaunay syndrome is a condition involving overgrowth of soft tissue and bone in a limb, along with abnormalities of veins and lymphatic vessels. In a study of 32 patients with the syndrome, 31 had lymphatic vessel or lymph node anomalies, and all 31 had lymphedema (chronic lymphatic swelling) in the affected limbs.²² For patients with this syndrome, the lymphatic malformation is just one piece of a larger puzzle that may also include port-wine stain birthmarks, varicose veins, and limb-length differences. Treatment needs to account for all of these overlapping issues, and a multidisciplinary team is even more critical.

Living With a Lymphangioma Over Time

One of the hardest things for families to hear is that lymphangiomas are rarely “cured” in the way that word is usually understood. Even after successful treatment, the underlying abnormal lymphatic tissue remains, and recurrence or partial regrowth is common. A large study following children with lymphatic malformations over 11 years at a single referral center emphasized the wide range of outcomes and the need for individualized, multidisciplinary care to achieve the best results.²³

In practical terms, “multidisciplinary” means a team that might include a pediatric surgeon, interventional radiologist, dermatologist, and sometimes an ENT specialist or geneticist, depending on the location and complexity of the lesion. Care tends to shift over time: an infant may need urgent intervention for airway compromise, a school-age child may need sclerotherapy for a growing cyst, and a teenager may need laser treatment for cosmetically troubling skin vesicles or sirolimus for persistent oozing. The condition is lifelong, but for most people the goal of treatment is long-term symptom control and prevention of complications rather than total elimination of the lesion. With the range of tools now available, from sclerotherapy and surgery to targeted drugs and lasers, that goal is more achievable than it was even a decade ago.