ConditionChildren's health
Lymphatic Malformation (Lymphangioma)
A lymphatic malformation is a non-cancerous mass of abnormally formed lymph vessels filled with fluid. It is present from birth, though it may not be noticed until it swells, and most are found before age 2. It usually appears as a soft, painless lump in the neck, armpit or face. The large, cystic type in the neck was once called a cystic hygroma. Lymphatic malformations do not spread like cancer, but they can swell suddenly with infection or bleeding and press on the airway. Sclerotherapy, surgery and the medicine sirolimus are the main treatments.
Also called: Lymphangioma, cystic hygroma (older term), lymphatic vascular malformation, macrocystic or microcystic lymphatic malformation
At a glance
- What it is
- A benign malformation of lymph vessels forming fluid-filled cysts, present from birth.
- Where
- Most often the neck and face; also the armpit, chest, limbs and internal organs.
- Types
- Macrocystic (large cysts), microcystic (tiny cysts infiltrating tissue), mixed.
- Symptoms
- A soft, painless lump that may swell suddenly with infection or bleeding.
- Diagnosis
- Ultrasound and MRI; sometimes found on prenatal ultrasound.
- Treatment
- Observation, sclerotherapy, surgery, and sirolimus for complex or extensive lesions.
When to get help
Call 911 or go to the ER
- Noisy breathing, difficulty breathing, or inability to swallow saliva in a child with a neck or chest lymphatic malformation
See a doctor within a day or two
- Sudden, rapid swelling, redness, warmth or pain of a known malformation, especially with fever (possible infection)
- A malformation that suddenly turns blue or purple and enlarges (possible bleeding into it)
- Swelling of the tongue that makes eating or breathing difficult
Book a routine appointment
- A soft, painless lump in a baby or child's neck, armpit or face
- A known malformation that is slowly getting bigger
- Discussing treatment options or timing
What a lymphatic malformation is
The lymphatic system is a network of thin vessels that drains fluid from tissues back to the bloodstream and carries immune cells. In a lymphatic malformation, part of this network forms abnormally during fetal development, creating channels and cysts that fill with lymph fluid but do not drain properly.
Many lymphatic malformations are caused by a change in the PIK3CA gene that occurs only in the affected tissue (not inherited). This discovery explains why medicines that act on this pathway, such as sirolimus and alpelisib, can help.
Lymphatic malformations are not tumors. They grow in proportion to the child rather than spreading, though they can enlarge with infection, bleeding or hormonal changes.
Types
| Type | Features | Treatment response |
|---|---|---|
| Macrocystic | Large cysts (generally over 1 to 2 cm), soft, translucent when lit from behind | Responds well to sclerotherapy |
| Microcystic | Tiny cysts infiltrating skin, muscle or tongue; may cause small blisters on the skin | Harder to treat; sirolimus often used |
| Mixed | Both | Combined approaches |
Complex lymphatic anomalies, such as generalized lymphatic anomaly and Gorham-Stout disease, involve multiple sites, including bones, and need specialist care.
Where they occur
- neck and face: the most common sites
- armpit and chest wall
- tongue and floor of mouth: can affect feeding, speech and airway
- eye socket: can push the eye forward
- limbs, abdomen and chest cavity
Symptoms
- a soft, spongy, painless lump under normal or slightly bluish skin
- swelling that varies in size, often enlarging with colds or infections
- tiny clear or blood-filled blisters on the skin surface (microcystic type)
- sudden swelling, pain and color change with bleeding into the cysts
- redness, warmth and fever with infection
- problems with breathing, swallowing, speech or vision, depending on location
Associated conditions
Large neck malformations found before birth (often called cystic hygroma) are associated with chromosomal conditions such as Turner syndrome and Down syndrome. Genetic testing during pregnancy is often offered when one is seen on prenatal ultrasound.
Diagnosis
- ultrasound: shows fluid-filled cysts, usually the first test
- MRI: shows the full extent and involvement of nearby structures, used for planning treatment
- prenatal ultrasound can detect some malformations before birth
- biopsy or genetic testing of the tissue in selected cases
A lymphatic malformation must be distinguished from a hemangioma (a blood vessel tumor of infancy that grows then shrinks), venous malformations, branchial cysts and lymph node swelling.
Treatment
Treatment depends on size, location, symptoms and type. Care is best provided by a vascular anomalies team.
- Observation: small, symptom-free malformations may not need treatment. Some macrocystic lesions shrink after infection or on their own.
- Sclerotherapy: an interventional radiologist injects a medicine (such as doxycycline, bleomycin or OK-432) into the cysts, causing them to scar and shrink. It is often the first-line treatment for macrocystic lesions and may need several sessions.
- Surgery: removal of the malformation, especially when well defined. Complete removal can be difficult because the cysts wrap around nerves and vessels, and recurrence is possible.
- Sirolimus: an oral medicine that blocks the mTOR pathway, used for microcystic, extensive or complicated malformations. It can reduce size and symptoms, with blood level monitoring.
- Laser treatment for skin blisters.
- Treatment of infections with antibiotics, and of flares with anti-inflammatory medicines.
- Airway support, sometimes including a tracheostomy for large neck lesions in newborns.
Outlook
Many children with lymphatic malformations do very well with treatment. Macrocystic malformations respond best. Microcystic and extensive malformations may need long-term management, as they can recur or swell during infections and puberty. Regular follow-up with a specialist team is important.
Frequently asked questions
What is a lymphatic malformation?
A lymphatic malformation is a non-cancerous, fluid-filled mass formed by abnormally developed lymph vessels. It is present from birth, most often in the neck or face, and may be noticed as a soft, painless lump.
Is a lymphatic malformation cancer?
No. It is a benign malformation, not a tumor, and it does not spread to other parts of the body. It can still cause problems by swelling or pressing on structures such as the airway.
What is the difference between a lymphatic malformation and a cystic hygroma?
Cystic hygroma is an older name for a large, macrocystic lymphatic malformation in the neck, often seen on prenatal ultrasound. The current preferred term for all types is lymphatic malformation.
How are lymphatic malformations treated?
Options include watching small ones, sclerotherapy injections to shrink cysts, surgical removal, laser for skin blisters, and the medicine sirolimus for extensive or microcystic lesions. Treatment is tailored by a vascular anomalies team.
Sources
This guide was written from current patient and clinical guidance, including:
- International Society for the Study of Vascular Anomalies (ISSVA): Classification of Vascular Anomalies (2018)
- National Organization for Rare Disorders (NORD): Lymphatic Malformations
- Lymphatic Malformation Institute: Patient information
- MedlinePlus: Cystic hygroma
- American Academy of Pediatrics: Clinical Report on Vascular Anomalies (Pediatrics)