Lymphatic malformation (LM) is an abnormal collection of lymphatic fluid within cysts or channels, usually in the soft tissue. It results from errors in development of the lymphatic tissue, usually confined to one area of the body. Lymphatic malformations (also called lymphangiomas) occur everywhere in the body, except for the brain. They are often classified according to the size of the fluid-containing components. Macrocystic LMs (cystic hygroma) are composed of large cysts (more than two centimeters in diameter), while a microcystic LMs have small cysts or soft tissue enlargement without visible cysts. Many patients have an LM with a combination of large and small cysts. Lymphatic malformations occur when the lymph vessels that make up the lymphatic system aren't formed properly and result in the defective transport of lymph and an abnormal collection of lymphatic fluid.
Diagnosing Lymphatic Malformations
LMs can often be diagnosed by clinical examination, especially if the skin is involved with vesicles or small blister-like raised areas. The involved skin is sometimes red or purple, like a port wine stain. A deep LM usually causes enlargement of the soft tissues that are affected. Sometimes, the neighboring veins are also enlarged. A magnetic resonance imaging scan is the most helpful diagnostic test to show the extent of the malformation and the number and size of the cysts. For an LM that is near the skin surface, ultrasonography also shows the cysts.
LMs present early in life, although they can also occur in young people or adults. The lesion may be progressive, at times relentlessly expanding with advancing age. In some patients, LMs enlarge more rapidly as the cystic cavities have ever more difficulty draining. There may be acute exacerbations with infections, such as upper respiratory infections or ear infections, among others. When seen in older patients, LMs have a tendency to expand much slower. Depending on their location, the growing cysts can also result in complications, such as infections (which can produce discoloration and a bruised or inflamed appearance) and impairment of breathing or swallowing.
Lymphatic Malformations Symptoms
LMs typically produce localized swelling and enlargement of the affected areas, but they do not involve the skin. These often present at birth and increase in proportion with growth of the individual. Occasionally, they can expand suddenly due to either infection or bleeding into the cysts. Symptoms vary depending on the location of the LM. Those involving the mouth can interfere with breathing and speech, while those in the arms in legs cause swelling and heaviness.
Treatment for simple macrocystic LMs is typically effective and the conditions rarely recur. Combined lymphatic, containing large and small cysts, are more difficult to treat. Any residual cysts can recur. Microcystic LM’s cannot be cured and may require ongoing treatment for swelling.
We typically treat LMs very early in life to avoid or diminish skeletal deformities. For macrocystic LMs, we perform either sclerotherapy or surgical removal. Microcystic LMs, especially those with no visible cysts, are more difficult to treat and generally require surgical removal or contouring.