Overview

Lymphangioma is a benign malformation of the lymphatic system that affects the skin and mucous membranes. The lymphatic system typically aids in the drainage of waste products and also helps in defence mechanisms. Oxygenated blood is typically carried by the arteries, while deoxygenated blood returns to the heart through the veins. The lymphatic system is a complex network composed of lymphoid organs, lymph nodes, and lymphatic vessels. These lymphatic vessels function as tubular channels that collect interstitial fluid, known as lymph, that has leaked from blood vessels (primarily arteries) into the surrounding tissues. This lymph is then filtered through lymph nodes and eventually returned to the venous circulation. If this drainage does not occur properly, it results in oedema or swelling.²

Lymphangiomas may be categorised by depth into superficial and deep types, or by origin as congenital or acquired lesions. It mostly appears in children, and in adult-onset lymphangiomas (AOL), it is rare and occurs due to trauma or some respiratory infections. It usually affects the lymphatic system that drains the neck, clavicle and axillary region.³

Origin and epidemiology 

The origin of the lesion is unclear; it is attributed to a developmental defect or cystic malformation of a dilated lymphatic channel.⁴ It is due to isolation or a defect in the proper connection of the lymphatic tissue from the lymphatic sac during the embryonic stage. This may cause a failure in the communication of the lymphatic or venous systems. Dilation of these lymphatic tissues causes a cystic structure. The origin of adult-onset lymphangioma is still debated. According to some authors, adult lymphangioma is due to delayed proliferation of the congenital or acquired lymphoid structures following trauma, or it can be a result of some respiratory infection.⁵ The congenital as well as early childhood lymphangiomas are often associated with genetic abnormalities and developmental malformations. Lymphangioma commonly occurs in children below the age of two years, and adult-onset lymphangioma is very rare.^4,5

Pathophysiology

The venous system usually carries blood back to the heart, and the lymphatic system drains the lymph into the venous system. The defect occurs in this step of the drainage, leading to the accumulation of lymph in the form of cystic structures. It can enlarge in size, and it can be due to the accumulation of lymph, due to secondary infection or hemorrhage.³

Clinical symptoms of adult vs childhood lymphangioma

The common locations are the neck region (75%), axilla, mediastinum, groin and also below the tongue. Based on the location of the swelling, there may be difficulty in moving the body parts, which can obstruct the respiratory system, pain, hoarseness of voice, dysphagia or even shortness of breath.  Sporadically, it may occur in the spleen, liver, kidney and intestine. It can be moved easily, and most importantly, it is translucent; i.e., if we pass a light through the swelling, it glows, which means it contains clear fluid. The swelling increases in size if a patient coughs or cries. It is non-neoplastic or non-cancerous.^3,4

In adult-onset lymphangioma, the symptoms are rare, and it appears as a well-defined mass often confused with a dermoid cyst, branchial cleft cyst, lymph node neoplasm or cystic metaplastic lymph nodes. Adults usually present with an asymptomatic, soft, fluctuant, well-defined mass with a capsule, but it is less defined in children. The symptoms caused due to compression are rare, and individuals get it removed mainly for cosmetic reasons.⁶

Rare presentations

There are some case reports with AOL, and most of it is present on the sides of the neck. Rare presentations that are reviewed in the literature are omental lymphangioma, laryngeal lymphangioma, axillary lymphangioma, scrotal lymphangioma circumscriptum, and abdominal lymphangioma. Some rare cases of AOL are:

• A 45-year-old female patient presented with atypical swelling in the neck region. Surgery was performed with the initial diagnosis of lymphatic cyst, branchial cyst and infected cyst or abscess, but turned out to be a lymphangioma⁷
• A 28-year-old female patient with a growing mass in the axilla, the initial diagnosis was hydatid cyst, but after excision, it turned out to be lymphangioma⁸
• A 22-year-old man with stomach distention and showing features of cancer, and on excision, it was found to be omental 
• lymphangioma⁹

Diagnosis 

Diagnosis can be difficult in the case of AOL, as it may mimic many other lesions. Imaging modalities such as USG(ultrasonography), CT( computed tomography) and MRI( magnetic resonance imaging). CT and MRI are used for treatment purposes to determine the exact size and location. It also helps in determining the proximity to important structures.³ The biopsy procedure is done to get a confirmatory diagnosis. Despite advancements in imaging techniques, the diagnosis of adult-onset lymphangiomas remains challenging. Definitive diagnosis can only be established through histopathological examination of the excised surgical specimen.^3,6

Treatment 

Surgery is one of the most common treatment options, but complete removal (resection) may not be possible in the case of deep-seated lesions. The incomplete removal may cause recurrence, hence deep-seated lesions are treated by drainage and sclerotherapy using agents such as bleomycin, tetracycline and triamcinolone. Laser therapy, radiotherapy and radiofrequency ablation are also used as treatment options. Imaging modalities can also be used in the treatment.^6,10

Summary 

Unlike congenital lymphangiomas, adult-onset cases are exceptionally rare and typically present with subtle symptoms that resemble those of more common lesions. A proper diagnostic test should be advocated to arrive at the diagnosis. The usual treatment options include surgery; however, if the lesions are deep-seated, procedures such as drainage, sclerotherapy, laser therapy, radiotherapy and radiofrequency ablations are performed. Incomplete surgical removal may cause recurrence. So, adult-onset lymphoma should be considered in the differential diagnosis of swellings. The physicians should be aware of such conditions and should receive appropriate training to diagnose them.