Lymphatic malformations, formerly called lymphangiomas, are fairly rare birth defects of the lymphatic system, appearing in the form of localized cysts.

These anomalies, which generally appear in early childhood, are benign but can have a significant impact, for example causing respiratory problems when they affect the ENT sphere. The management is difficult and frequent recurrences.

Definition

Lymphatic malformations, formerly known as lymphangiomas or cystic lymphangiomas, are birth defects that develop at the expense of the lymphatic system.

The lymphatic system is a vascular network made up of fine vessels, which carries lymph from most of the body’s organs to the lymph nodes. It contributes in particular to the purification of cellular waste as well as to the transport of certain nutrients and white blood cells, thus playing an essential role in immunity.

Lymphatic malformations are characterized by the presence of cysts in the form of lymphatic pockets, superficial (involving the skin, mucous membranes or underlying tissues) or deep. They are localized in the head and neck in more than half of the cases, but can be lodged almost everywhere in the body, in particular in the region around the armpits and more rarely in the thoracic, abdominal or pelvic viscera.

We distinguish the macrocystic forms, with a size greater than 1 cm and sometimes much larger, microcystic forms (size less than 1 cm).

• The macrocystic forms are by far the most frequent. Although limited, these macro-cysts can be isolated or multiple, or even associated with each other. They appear as soft, elastic masses under normal skin. They evolve in spurts.
• The microcystic forms take on the appearance of poorly delimited plaques invading the skin and mucous membranes, dotted with small vesicles (blisters) filled with clear or bloody fluid.
• There are also mixed forms.

These lesions are always benign, even when they form pseudo-tumor masses. Most are already present at birth and evident before the age of 2 years. However, latent cysts can develop at any time and do not appear until adulthood.

The severity is due to the size, location and evolution of the malformations. Their spontaneous regression is possible, but frequently they compress the surrounding tissue and can have repercussions on vital functions.

Causes

Although the causes of the appearance of lymphangiomas are not fully understood, their congenital origin is now widely accepted. During the formation of the lymphatic system during embryonic life, an abnormality in the development of lymphatic network structures is believed to occur under the influence of genetic and other extrinsic factors. Certain genes involved in the proliferation and abnormal nature of lymphatic vessels have already been identified, and research is continuing.

Diagnostic

Diagnosis involves ultrasound and MRI (magnetic resonance imaging), which is more efficient at visualizing the precise extension of lesions and their penetration into surrounding tissues. CT (computed tomography) can replace MRI.

Prenatal diagnosis is sometimes performed on ultrasound from the fourth month of pregnancy. If there is a large lesion, a fetal MRI may be performed in the last trimester to prepare for delivery.

If in doubt, a fine needle aspiration (removal of cells using a fine needle) will confirm the diagnosis.

The people concerned

The incidence of lymphangioma is difficult to assess. Authors consider it to be a rare condition (1 in 16 births to 000 in 1 births). However, the French ENT and Face and Neck Surgery Society (SFORL) puts forward the figures in 2000 of 2018 to 1,2 cases of lymphangiomas of the face and neck per 2,8 births.

About half of lymphangiomas are present at birth and nine in ten are diagnosed within the first two years of life.

Risk factors

Lymphatic malformations often appear in isolation, but can also be part of syndromes caused by genetic abnormalities or chromosomal disorders: Noonam syndrome, Turner syndrome, trisomy 21, trisomy 18, etc.

An old study suggests a possible link between fetal alcoholism and the development of a lymhatic malformation.

The symptoms and functional repercussions of lymphangiomas depend on their size and their location, and may be aggravated by complications (inflammation, etc.). The clinical presentation of this pathology is therefore very polymorphic, with in some cases a total absence of symptoms, in others an aesthetic discomfort or a limited functional impact (for example difficulty in dressing in the event of localization in the armpit). ), in still others impairment of vital functions.

Flare-ups, secondary infections and bleeding

In macrocystic forms, inflammatory flare-ups result in swelling, redness and pain in the lymphangioma accompanied by fever. They can cause secondary infections and bleeding.

The microcystic forms can also bleed or become superinfected.

Lymphangiomas of the face and neck

Localization in the mouth, tongue or larynx can have various consequences: deformation of the jaw with joint disorders, difficulty swallowing and eating, breathing problems … These problems can be serious especially in case floor of the mouth or compression of the larynx and trachea. They can be increased by the occurrence of complications, and frequently require hospitalizations.

malformation near the eye sometimes results in visual disturbances

Thoracic lymphangiomas

In the most severe cases, they are likely to be the cause of chest effusion (chylothorax) or of heart and lung complications.

Intra-abdominal lymphangiomas

Revealed on palpation by the presence of an abdominal mass when they are large, intra-abdominal lymphatic malformations are frequently the cause of abdominal pain. Sometimes they cause bigger problems like volvulus (a twist of the intestine).

The management and treatment of lymphangiomas can be difficult and are not the subject of standardized procedures, the treatment decision having to be adapted on a case-by-case basis. Treatment abstention associated with close medical monitoring is possible for asymptomatic lesions which are likely to regress spontaneously.

Medical treatment

Complications of lymphatic malformations are controlled by medical treatment with antibiotics, anti-inflammatory drugs and painkillers.

Sclerotherapy

This option is often preferred. After puncture of their contents, various sclerosing products, in particular alcoholic derivatives, are injected into the cysts in order to cause their retraction and their stiffening. This intervention is performed by a specialist under local or general anesthesia.

Side reactions (inflammation, edema, skin ulceration, etc.) are possible and must be treated.

Several sessions may be necessary for large cysts. Recurrences, which are frequent, remain accessible to sclerotherapy

surgery

Surgical removal of cysts is most often considered after failure of sclerotherapy, or in microcystic forms not accessible to sclerotherapy. The efficiency is rather good, but some lymphangiomas are difficult to extirpate and the risk of complications (paralysis by nerve damage, hematoma, etc.) must be carefully weighed.

Recurrences are not uncommon.

Other treatments

Various alternative treatments to sclerotherapy and surgery can be considered to respond to specific situations:

• Treatment by laser (CO2 laser, Nd-YAG or diode) or by radiofrequency can be useful in reducing certain lymphatic malformations located in the superficial mucosa.
• Cryotherapy (destruction by cold) can be considered to safely resolve seepage problems.
• Various systemically administered molecules have been tested, with overall disappointing results so far in studies:

  – Sirolimus (rapamycin) would be effective simultaneously on all localizations, and can be tried in case of failure of local treatments

  – Propanolol could be of some interest in treating bleeding mucosal lesions.

  – The other molecules (Interferon a-2b, sildenafil, beta-blockers) have not been shown to be effective.

Lymphangioma cannot be prevented, but actions can be taken to prevent complications by limiting exposure to the risk of viral or bacterial infection as much as possible. In particular, strict dental hygiene rules must be adopted.