Introduction

Cavernous lymphangioma is a harmless, non-cancerous growth formed due to the abnormal development of lymphatic vessels. It is categorised under lymphatic malformations. The lymphatic system is the plumbing system of the body, which helps in draining lymph, which is a fluid enriched with white blood cells, and aids in immunity. If there is an improper development of the lymph vessels during foetal growth, they can clump into masses that present as lymphangiomas. Cavernous lymphangiomas are characterised by large, hollow lymphatic channels.¹

Lymphangiomas are congenital; that is, they are present at birth or develop shortly after birth. Hence, it is commonly identified in children under two years of age.¹ Lymphangiomas are generally benign (non-cancerous) and hence not life-threatening. But it possesses challenges as it presents mainly in the head and neck region. They can interfere with breathing, eating or speech. Such complications make the diagnosis and management of this condition crucial. 

Recent advancements in imaging and treatment have greatly enhanced outcomes for patients affected by this condition.² In this article, we will explore more about the diagnosis and management of this condition.

Pathophysiology and Classification

Cavernous lymphangiomas are birth defects that occur during foetal development. The primary lymph sacs fail to connect with the large vessels and result in lymph accumulation in the improperly formed vessels.¹ These vessels grow over time, resulting in palpable masses.

When examined under the microscope, cavernous lymphangiomas consist of large, dilated lymph spaces situated in the connective tissue. These channels are lined with a single layer of endothelial cells and may contain fluid rich in proteins. Lymphatic vessels do not contain red blood cells and have thin, permeable walls which aid these growths.³

Lymphangiomas are categorised into three main types based on the size and structure of the lymphatic channels involved:

• Capillary (Simplex) Lymphangioma – These are made up of small, capillary-sized lymphatic channels and are typically found in the skin or mucous membranes
• Cavernous Lymphangioma – Defined by large, dilated lymphatic spaces often situated in deeper tissues, these types are less apparent on the surface and can grow to significant sizes
• Cystic Hygroma (Macrocystic) – These are large, cyst-like formations filled with clear fluid. They usually occur in the neck and axilla and are frequently diagnosed either prenatally or shortly after birth¹

Cavernous lymphangiomas have a sponge-like structure. Diagnosis and treatment become complicated in mixed forms.

Aetiology and Risk Factors

It's still not clear exactly how cavernous lymphangioma starts in most cases. These issues are thought to be present from birth. This means they happen before a baby is born and are not caused by anything outside the body. They are not linked to the mother's health, things in the environment, or infections during pregnancy. However, some lymphangiomas, especially large cystic hygromas in the neck, have been linked to problems with chromosomes and genetic disorders.¹

Cavernous lymphangiomas have been seen in people with Turner syndrome, Noonan syndrome, and Down syndrome.⁴ These genetic conditions often cause other developmental problems. These can include problems with how lymph fluid drains or how blood vessels form.

Cavernous lymphangiomas are usually there when a baby is born. But they might not be noticed until the child is older, when they get bigger or cause symptoms. Things like injuries, changes in hormones, or infections can cause a lesion that was not noticed before to grow quickly or become inflamed.¹ These additional problems can make treatment harder and increase the chances that medical intervention will be needed.

Clinical Features

Cavernous lymphangiomas are commonly present in the head and neck, especially in the mouth, including the tongue, lips, and the bottom of the mouth. They can also be found in the armpit, arms or legs, torso, or inside the body in places like the mediastinum and mesentery, but this is not as common.^1,2 In adults, these growths are usually small and located in the mouth or neck.²

Cavernous lymphangiomas are soft, painless lumps that can be pressed down easily. They may look normal or have a slightly bluish tinge. Transillumination, which involves shining light through the lump, often shows a glowing effect due to the presence of clear lymphatic fluid inside.³ Lumps that are deep inside the body may not be visible, but they can be felt as spongy masses under the skin.

Large growths can cause problems depending on their location. Masses in the oral cavity hinder speech and swallowing. In the airway or oesophagus, they can cause trouble with breathing or swallowing. Infections are common, especially if the growth is on the surface and can be easily injured. Also, bleeding and sores can happen, especially after the growth breaks open or after surgery.^2,3

Diagnostic Evaluation

The diagnosis starts with a full review of the patient’s medical history and a physical checkup. Doctors usually check the size, location, feel, and any symptoms related to the problem area. Because lymphangiomas are problems with blood vessels, imaging is needed to confirm what it is and plan how to treat it. An ultrasound is often the first imaging method used. It can find pockets of fluid and tell lymphangiomas apart from solid tumours.⁵

Doppler imaging helps check blood flow to rule out blood vessel problems like hemangiomas.

MRI is the best imaging method for cavernous lymphangiomas. It gives a better view of soft tissues and helps show how far the problem goes, how deep it is, and how it relates to nearby body parts. MRI can also tell lymphatic problems apart from other soft tissue tumours and help with planning surgery.⁵ CT scans are used for complicated or deep problems, especially when there's a concern about bone involvement or airway compression. Although CT scans give detailed pictures, they are not used as much because of radiation exposure, especially in children. Looking at tissue under a microscope confirms the diagnosis after a problem area is removed. Tissue samples show typical widened lymphatic channels with thin walls and clear or protein-rich fluid. Special staining for markers like D2-40 can tell the lymphatic lining from blood vessels.⁵             

Differential Diagnosis

Some similar conditions which mimic cavernous lymphangioma are:³

• Hemangioma—Benign tumour of the blood vessels, often seen in babies. Unlike lymphangiomas, they have a lot of blood flow and grow quickly in infancy, then shrink
• Cystic Hygroma—A type of lymphatic malformation with large cysts, usually in the neck. These problems are more like cysts and bigger than cavernous lymphangiomas
• Lipoma—A harmless tumour of fatty tissue, usually soft and movable, but light does not shine through it
• Dermoid Cyst—A swelling or growth present at birth that contains skin and hair parts, often feels firmer than lymphangioma
• Venous Malformation—Usually looks bluish and can be compressed, has slow blood flow as seen on Doppler imaging    

The correct diagnosis is arrived at by examining imaging results and pathological samples.                      

Management Strategies

The treatment plan depends on various factors such as the size, symptoms, location and age of the affected person. Small, asymptomatic growths usually need no treatment as they go away on their own. It doesn't just disappear completely.¹

Non-surgical treatments include:

• Sclerotherapy—Substances such as OK-432 (Picibanil), bleomycin, or doxycycline are injected directly into the growth. These substances cause swelling and scarring, which slowly shrink the lymphangioma. Sclerotherapy works well for growths on the surface and deeper inside and is often used as the main treatment or to help with surgery⁴
• Laser Therapy—Carbon dioxide and Nd:YAG lasers can be used for lymphangiomas on the surface, especially in the mouth. They offer precise tissue removal without much bleeding¹
• Surgery—Large infectious growths need surgery as they interfere with health. The entire growth can be removed by surgery. But it is complicated if the growth is adjacent to vital organs or blood vessels, as they risk bleeding, which can be fatal. Incomplete removal may result in recurrence² 

A combination of sclerotherapy and surgery is often used for complicated or recurring cases. Interventional radiologists can use imaging to guide sclerotherapy or drainage, making it more accurate.⁵ 

Prognosis and Follow-Up

The prognosis is usually good, especially when it is found and treated early. Surgery often cures growths that are in one place. However, the growth can come back in 10% to 27% of cases, especially if it spreads out or isn't completely removed.⁶ General well-being and the location of the growth are determining factors in the prognosis of this condition. Treatment should focus on removing the growth and keeping or restoring normal function and appearance. It's important to monitor patients long-term, especially children, to check for any recurrence and adapt a customised treatment plan. The best care is provided by a team of experts, including paediatricians, surgeons, radiologists, and specialists in speech or swallowing therapy.⁶                         

Summary

Cavernous lymphangiomas are rare masses found congenitally. Though non-cancerous, the size and the location cause concern. It is crucial to know its types, causes and symptoms to manage them effectively. Early diagnosis, customised treatment plans and better imaging procedures often give good recovery results. Regular monitoring and a multi-system approach are keys to managing complex cases.