Introduction

Lymphangiomas are an uncommon type of benign malformation of the lymphatic system that occurs on the skin and mucous membranes. This condition is present at birth or can develop in early childhood due to abnormal growth of the lymphatic vessels. This abnormal growth is composed of lymphatic fluid and varies in size and appearance, depending on its type and location. 

While this malformation is benign, lymphangiomas can cause detrimental health issues, such as compression onto nearby structures or rapid expansion in size. This means that early recognition is crucial, allowing for early treatment to be applied before complications develop.¹

Types of lymphangioma

Lymphangiomas can be classified into 3 types based on their histology:

• Capillary (Simple) - They are situated close to the surface of the skin and are made up of small, thin-walled lymph vessels
• Cavernous - These consist of larger lymph vessels that are connected to normal lymph vessels located nearby
• Cystic Hygroma - Consisting of lymphatic spaces varying in size, these contain clear, milky, bloody or pus-like fluid, and are not connected to nearby normal lymph vessels^2,3

Lymphangioma sites in infants and young children

While lymphangiomas are mainly found in the head, neck, and oral cavity, they can also be seen at other sites. Some rarer sites include:

• Axilla (armpit)
• Chest or abdominal wall
• Mediastinum or retroperitoneal space

Clinical presentation

Lymphangiomas are most commonly present between birth to 5 years old.⁴ 

They appear as a painless, visible, soft mass under the skin and differ in size and colour depending on the type and location. For example:

• Cavernous lymphangioma is a rubbery, swollen mass, which is red to blue in colour. These masses are most commonly present on the tongue
• Cystic hygroma is a reddish-blue, fluid-filled, enlarged mass typically observed on the neck, groin or armpit
• Lymphangioma circumscriptum is a smaller collection of pimple-sized, fluid-filled blisters that can be observed on the mouth, shoulders, neck, arms, and legs. They can range in colour, from clear to red to black

Although benign, lymphangiomas rapidly grow in size, especially in the case of viral infection or trauma. It then gives them the ability to infiltrate surrounding structures, leading to serious effects and long-term health issues.⁵

Diagnosis

Ultrasounds are applied to identify cysts before birth, allowing lymphangioma detection during pregnancy. In 50-60% of cases, a prenatal ultrasound is able to detect lymphangiomas, and in 90% of postnatal cases.⁶ This can help determine whether the lymphangioma is cystic or solid. Once the baby is born, the doctor will further examine the cyst and may order an MRI or ultrasound to measure the lymphangioma’s size and aetiology. It will also help identify any involvement of the lymphangioma in surrounding tissues.

For fetuses identified with lymphangioma, doctors should also perform a detailed ultrasound to check for other physical birth defects. Consequently, a karyotype study of the umbilical cord blood or amniotic fluid is recommended to detect chromosomal abnormalities.

Fine needle aspiration (FNA) is rare but may be performed to sample fluid within the mass. It is especially the case when there is uncertainty regarding the lymphangioma or to rule out other conditions.^7,8

It is important that accurate prenatal diagnosis and frequent monitoring of infants with lymphangioma take place to help improve prognosis and prevent major complications.

Complications

A common complication of lymphangiomas is attributed to an infection of the lesion. Infection of lymphangiomas can lead to an increase in size and may cause symptoms such as pain and difficulty breathing, specifically if the lesion is in the neck or chest. Surgical intervention may be required as infection of the lesion can lead to septic shock. Infected lesions may lead to further secondary complications such as lymphoedema.^9,10

Another possible complication is bleeding into the cyst. It causes the cyst to swell rapidly, which leads to pressure on the surrounding tissues that induces further feeling of pain. 

Swelling caused by these initial complications can trigger further problems, especially when compressing on nearby structures. This is especially concerning when located near the airway, which can lead to complications with breathing, or near the digestive tract, which can result in problems in swallowing.^11,12

Lymphangioma occurring in visible areas such as the face or neck may also lead to the child facing psychosocial challenges, such as low self-esteem or social anxiety. These challenges can impact the mental health of the child over time, possibly making it difficult in social settings like school. 

The mental and physical complications of lymphangiomas should thus be managed with the same gravity, with the involvement of counsellors and support groups that are available to help children and families cope.

Management options

When a lymphangioma is deemed small and asymptomatic, there is no need for treatment. Instead, “watchful waiting” and observation are encouraged. This involves regular monitoring via ultrasounds will be critical to assessing the lymphangioma’s growth and development. 

In cases where the lymphangioma is large, symptomatic, and causing additional problems to surrounding structures, surgery may be necessary to remove the cyst. However, the recurrence rate following surgery tends to be high, especially in  cases where partial excision or incomplete removal of the cyst is performed.¹³

When the lesion cannot be easily removed by surgery, Sclerotherapy is a common treatment option. It is the recommended treatment option for lymphangioma, where the cysts are greater than or equal to 1 cm in diameter, or for lesions that penetrate adjacent tissues. Sclerotherapy involves a sclerosing agent (such as OK-432) being injected directly into the lymphangioma. It causes the lining of the cysts to be irritated and eventually shrink over time (13). Sclerotherapy presents several advantages over surgery, such as less damage to adjacent healthy tissues, contributing to a shorter recovery time in the hospital.  

In specific cases, laser therapy or radiofrequency is a treatment pathway available. These procedures are done when the lesion is small or superficial or when it is located in areas such as the mouth. These methods involve using either laser light or radiofrequency waves to shrink and destroy the malformation.¹⁴

Prognosis

Generally, the prognosis for children with lymphangiomas is good, considering that early diagnosis of the condition and proper treatment have been given. In cases where surgery and sclerotherapy are necessary, significant improvements in function and appearance have been observed.

However, the risk of recurrence remains present. Incomplete resection of the lymphangioma is the main cause of recurrence, as doctors try to avoid removing excessive healthy tissues during surgery. 

Multidisciplinary management and long-term follow-up may be required to help manage treatment, monitor recurrence, and provide support. This ensures optimal outcomes for the child’s health and well-being.

Summary

• Lymphangioma is an uncommon benign lump in the skin (cyst) that is filled with fluid
• The abnormality occurs when the lymphatic vessels do not develop normally or when there is a defect in the connection between the lymphatic vessels and the veins
• The main sites of lymphangiomas are on the head, neck, and oral cavity of children
• The cysts typically appear between birth to 5 years old
• Lymphangiomas are most commonly diagnosed via ultrasound and physical examination, but can require more precise techniques such as Fine Needle Aspiration
• Lymphangiomas may not always require treatment in cases where it is not causing any harm to the child. However, treatment options such as surgery and sclerotherapy remain available where it is necessary