Introduction

Lymphangiomas are rare, benign lymphatic abnormalities (problems in the lymph vessel system that drains fluid and fights infection) that can appear anywhere on the skin and mucous membranes.^1,2 They may be congenital (present at birth due to abnormal lymphatic development) or acquired (develop later in life). The neck region accounts for most cases (75%), particularly in congenital forms. Depending on their depth and structure, lymphangiomas may appear as small clusters of fluid-filled blisters or larger sponge-like masses. Understanding their underlying cause helps distinguish congenital types from those that develop secondarily.

Understanding the Condition

Lymphangiomas are isolated areas of lymphatic tissue that are formed after the sixth week of pregnancy, when developing lymphatic tissue fails to anastomose (connect or join) adequately.^3,4 Lymphangiomas can be deep or superficial, depending on the depth and size of the abnormally formed lymph vessels, as well as congenital or acquired. 

Cavernous lymphangiomas (large, sponge-like clusters of lymph vessels) and cystic hygromas (fluid-filled sacs that form from blocked lymph vessels) are two distinct, well-defined congenital abnormalities that are classified as deep types of lymphangiomas.¹

Acquired lymphangioma, also known as lymphangiectasia, and lymphangioma circumscriptum (clusters of small blisters on the skin formed by dilated lymph vessels) are examples of superficial forms of lymphangioma. The term 'lymphangioma circumscriptum' implies lymphatic channel dilatation as a result of a congenital abnormality of the lymphatic system, despite the fact that both entities have comparable clinical and histologic characteristics.¹

In contrast, acquired lymphangioma refers to dilated lymphatic channels of formerly healthy lymphatics that have become blocked by an outside factor.¹

To explain the origin of this condition, three explanations have been proposed. These are:⁴

• The first postulates that the primitive lymphatic sac (early structure that forms lymph vessels) does not reach the venous system
• The second is that the normal growth of the primitive lymph channels (early lymph vessels) is blocked or arrested during early development of the embryo
• The third is that the lymphatic tissue is located in the incorrect location during embryogenesis (the process of development of an embryo)

What is a congenital lymphangioma?

Although the exact reason is still unknown, congenital lymphangiomas develop when the lymphatic system becomes blocked during foetal development.¹ This is the general term for any birth-related lymphatic abnormality. These deformities can take many different forms, such as lymphangioma circumscriptum, cavernous lymphangiomas, and cystic hygromas.²

According to the vessel depth, the congenital variants are likewise separated into two categories. Cavernous lymphangioma is the deep type, while lymphangioma circumscriptum is the superficial type.⁶

Pathophysiology

The congenital type, which typically manifests before the age of five, is caused by the incorrect attachment of the lymphatic channels to the central lymphatic drainage duct (the main vessel that returns lymph to the bloodstream).

Multiple, clustered or dispersed, transparent or haemorrhagic vesicular papules (small fluid-filled or blood-filled skin bumps) that resemble frog spawn are the clinical manifestation of lymphangioma circumscriptum. Purple patches can be visible sporadically among the vesicle-like papules because the lesions are made up of both blood and lymph components.¹

Cavernous lymphangiomas typically present in infants as a painless, ill-defined subcutaneous swelling (lump under the skin) that is several centimetres in size and does not alter the surrounding skin. In rare cases, the whole extremity (arm or leg) may be impacted. When the area is deeply palpated (pressed or examined by touch), patients may report feeling tender.¹

Cystic hygromas are lymphatic abnormalities that typically develop in the neck, axillae, or groin. A visual examination reveals that they are soft, come in a variety of sizes and shapes, and will usually grow if not removed surgically.

Cystic hygromas (fluid-filled cysts formed by blocked lymph vessels) usually occur at the site of lymphatic-venous collection (where lymph vessels connect with veins) and have an embryological origin. This explains why they frequently appear in the neck's posterior triangle (area on the side of the neck). A cystic structure is eventually formed as a result of the accumulation of lymph brought on by this breakdown in the connection between the lymph and venous routes.

Clinical Presentations

• Cystic hygromas often enlarge, and they can cause airway blockage in babies
• The primary indications for treatment include infection, respiratory distress, and cosmetic concerns²
• Typically, the patient will have a big, painless lump when they first arrive. The practitioner should determine when the lump was initially observed when taking the patient's history. This would be consistent with cystic hygroma if the onset occurred at birth or before the child turned two

The patient may exhibit dysphagia, shortness of breath, hoarseness, or discomfort. When major neck structures, including the voice box, trachea (windpipe), oesophagus, or large vessels, are compressed, these symptoms may ensue. Patients may or may not additionally report that their neck movement is restricted.²

What is acquired lymphangioma?

When acquired lymphangioma circumscriptum coexists with persistent lymphoedema, the previously normal lymphatic pathways are disrupted.¹ The uncommon disorder known as acquired lymphangioma, or acquired cutaneous lymphangiectasia, is typified by the abnormal enlargement of skin lymphatic vessels.¹

Various reasons, including trauma, surgery, or chronic inflammation, can disrupt the standard lymphatic drainage system. While acquired lymphangiomas arise later in life as a result of internal or external events that impact the lymphatic system, congenital lymphangiomas are present from birth.³

An obstruction causes the acquired form to manifest with dilated lymphatic channels. Whether or not these lesions are excised, they have a high likelihood of recurrence but no danger of malignant change.⁶

Causes

Acquired lymphangiomas can have a variety of causes, such as:³

• Surgery, particularly when it involves the lymph nodes
• Trauma or injury to the skin and surrounding tissues
• Infections or parasite infestations
• Prolonged inflammatory diseases like psoriasis or eczema

Epidemiology

The acquired form of cutaneous lymphangioma circumscriptum frequently manifests in adulthood, whereas lymphangiomas usually appear at birth or during the first few years of life.¹

Pathophysiology

Any disruption of previously normal lymphatic outflow, including radiation therapy, cancer, trauma, and surgery, can result in acquired lymphangiomas.

The armpit, groin and vaginal regions are where the acquired form is most frequently observed, and lymphoedema often coexists with it. Pruritus (itching), discomfort, burning, lymphatic discharge, infection, and cosmetic issues are possible concomitant symptoms.¹

Clinical Presentation

Clinical presentation include:³

• Tiny (small raised bumps) or vesicles (tiny fluid-filled blisters) that are transparent or bluish
• Growths that are rough and wart-like, particularly when linked to chronic inflammation
• Areas where skin fibrosis or thickening occurs. They can appear anywhere on the body; depending on the underlying cause of the disease, these lesions are usually found on the limbs. In the affected area, symptoms could include itching, soreness, or a heavy sensation

Evaluation

Imaging may be necessary to determine the breadth and depth of a lesion, and dermoscopy and biopsy can be utilised to confirm the diagnosis.

Treatment 

Treatment for both superficial and deep lymphangiomas can be challenging. However, surgical excision is still the preferred treatment for any kind of lymphangioma when it is practical. Since recurrence is frequent, extensive local excision of the impacted lymphatic pathways is required.¹

Preventing superinfection of fractured vesicles requires frequent cleaning of the affected area.⁶

There have been reports of symptom improvement following destructive procedures using electrosurgery, long-pulsed Nd-YAG lasers, and carbon dioxide (CO₂) lasers. 

Less often used techniques include sclerotherapy with 23.4% hypertonic saline, superficial radiation, and cryotherapy. A sclerosing substance, such as ethanol, doxycycline, or sodium tetradecyl sulfate at 1% or 3%, can be directly injected into lymphatic abnormalities. Compression may lessen lymphoedema-related swelling. Preventing infections is essential.¹

Cystic hygromas that develop into abscesses will require antibiotics, antipyretics, and analgesia, with or without subsequent surgical management.

Treatment for  acquired lymphangioma includes;

• Conservative care, such as wound care and compression therapy
• Laser therapy to minimise the size and look of lesions
• Surgical excision in extreme situations or when alternative therapies are ineffective
• Taking care of underlying illnesses, like inflammatory or infectious diseases

Sclerotherapy using OK-432 has emerged as the preferred treatment for these lymphatic abnormalities in recent years.⁵

For recurrences, sclerosing therapy must be taken into account.⁵

Complications

The two most frequent side effects of lymphangioma circumscriptum are lymphatic fluid leaking and cellulitis.¹ The cystic hygroma's quick growth may result in complications, including neck invasion. This may lead to obstructive sleep apnoea, dysphagia (difficulty swallowing), and partial or total airway blockage.²

Although accompanying chronic lymphoedema puts the patient at risk for lymphangiosarcoma, an aggressive tumour with a poor prognosis, acquired lymphangiomas are thought to have no malignant potential.¹ Poor lymphatic drainage can result in bacterial infection, and acquired lymphangiectasia can cause pain.

Summary

Lymphangiomas are uncommon congenital lymphatic system abnormalities that can develop at any age or location. Due to their tendency to invade and spread throughout nearby tissues, lymphangiomas usually present surgical obstacles and difficulties. A paediatrician, surgeon, dermatologist, and primary care physician work best as an interprofessional team to treat this condition. Although sclerotherapy (injecting a chemical into the lesion to shrink it) has been suggested as a substitute to lessen the effects and problems of surgery, surgical removal is still the best recommended treatment for lymphangiomas. To prevent problems caused by delayed presentation, patient education is essential.