Lymphatic malformations

Lymphatic malformations are also known as Lymphangiomas or Cystic Hygromas. Lymphatic malformations occur when the flow of lymph across a region slows down. It is believed that the mechanism that transports the lymph is defective. Lymph will accumulate within these defective vessels and this presents as a mass.
The mass will vary in size depending on the area of involvement. The mass is usually firm and is not compressible. If there is skin involvement, small vesicles can be found on the surface. If mucosa is involved, the same fluid filled vesicles can be seen. Since the flow of lymph can fluctuate, any condition that increases the amount of lymph will cause an increase in the size of the lesion. These include infections (usually viral), hormonal changes (pregnancy and puberty) and trauma. Lymphatic malformations can be made up of large cysts (macrocystic) or small cysts (microcystic).

The natural history of lymphatic malformations is relentless expansion with advancing age. Some will enlarge more rapidly than others. These we call high grade lesions. Low grade lesions are less active, present later in life and expand much more slowly. The physiologic process that differentiates these 2 groups is unknown.

Laser treatment

Lasers are primarily used to treat the vesicles (small blisters) that appear on the surface of the tongue and mucosa of the mouth. We use a CO2 laser for this. These patients experience significant symptoms as a consequence of these vesicles. Vesicles frequently rupture and a blood stained lymph will leak from these sites. In addition to this, these patients are unable to eat any acidic, carbonated or spicy foods since they experience a burning sensation.

Since the lymphatic malformation may involve the entire thickness of the tongue, this treatment may not be curative, but it significantly improves the quality of life of the patient. The treatment is administered under general anesthetic and is usually done every few years. After a patient heals, most or all of the vesicles disappear.

Surgery and sclerotherapy

Two forms of treatment are used to treat lymphatic malformations, sclerotherapy and surgery. In general, sclerotherapy is effective in treating macrocystic lesions but less effective for microcystic lesions. Substances used in sclerotherapy include OK432, Doxycline and a number of alcohol derivatives. These agents cause an irritation of the wall lining the lymph cyst which then becomes inflamed and shuts down. In order for the agent to be effective, it must come into contact with the lining of the cyst. This is much more difficult when dealing with microcystic lesions.

Surgical resection of lymphatic malformations can be undertaken, and in treating macrocystic lesions, is curable. With respect to microcystic lesions, recurrence rates are usually high and multiple procedures are usually necessary. The experience of the surgeon is extremely important, especially when dealing with lesions that involve the facial nerve.