Lymphatic Malformation

The lymphatic system consists of vessels that move lymph, a fluid made of proteins, fat particles and white blood cells that help to protect against infection and disease. A lymphatic malformation consists of enlarged fluid-filled lymphatic channels that do not connect to the normal lymphatic system. This causes swelling in the area in which the malformation is located.

These masses are usually apparent at birth. They used to be called lymphangiomas or cystic hygromas.

There are macrocystic and microcystic types based on size of the cyst. Combined macro and microcystic forms also exist.

Symptoms and history

Lymphatic malformations grow in proportion with the body and usually are asymptomatic but will present as focal swelling, pain and tenderness due to infection or bleeding within the malformation.

Diagnosis

Clinical Exam. A lymphatic malformation typically presents as an asymptomatic, soft, partially compressible focal swelling. If it’s situated in the cervico-facial region (face and neck) it might cause life-threatening airway obstruction and feeding difficulties. Bone involvement leads to skeletal enlargement and deformity.

If it is localized around the eye, it may cause proptosis (push the eye forward), increased intraocular pressure, strabismus, diplopia and even vision loss. Intra-abdominal lymphatic malformation may present as an abdominal mass, pain and distension as well as act as a lead point in bowel obstruction. The skin lesions may present as vesicles or blisters resembling warts and may ooze a clear or bloody liquid.

Imaging. First line imaging is ultrasound, showing oval and round cystic lesions with no blood flow on Doppler. If there’s internal cystic bleeding then it might have a fluid-fluid level, like a cup of oil in water. MRI (Magnetic Resonance Imaging) is helpful to show the extent of the lesion, especially involving areas that are difficult to ultrasound, like the face or deep intrabdominal region.

Pathology. Usually there is no need for biopsy and tissue evaluation as the history and imaging studies are enough for diagnosis.

Genetics. In most cases, lymphatic malformations are isolated without a clear genetic explanation. Sometimes they may be part of a genetically defined syndrome like Turner or Noonan or have DNA abnormalities encountered only in the body area affected by the lymphatic malformation (somatic mutation).

Treatment

Your child's lymphatic malformation can be treated in multiple ways:

• Emergent decompression, sclerotherapy, or surgical excision may be required if airway or vision is compromised.
• Asymptomatic lymphatic malformations can be clinically monitored.
• Symptomatic lymphatic malformations can be treated with sclerotherapy, surgical excision, and laser therapy if the skin or mucosal surface is affected
• Complex lymphatic anomalies or those associated with other complications (like overgrowth) may be eligible for medical therapy in clinical trials
• Surgical excision may be needed.