Lymphatic malformation (LM) is an abnormal collection of lymphatic fuid 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 (sometimes referred to as lymphangiomas or cystic hygroma) occur everywhere in the body, except for the brain. They are often classified according to the size of the fluid-containing components. Macrocystic LM (cystic hygroma) is composed of large cysts (more than 2cm in diameter) while a microcystic lymphatic malformation has small cysts or soft tissue enlargement without visible cysts. Many patients have an LM with a combination of large and small cysts.

LM (cystic hygroma and lymphangioma) 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. The deep LM usually causes enlargement of the soft tissues that are affected. Sometimes, the neighboring veins are also enlarged. An MRI scan is the best 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 demonstrates the cysts.

Lymphatic malformations typically produce enlargement of the effected the tissues. This is often present at birth and increases in proportion with the growth of the individual. Occasionally, they can expand suddenly due to either infection or bleeding into the cysts. Symptoms in general depend on the location of the lymphatic malformations. Those involving the mouth and airway can interfere with breathing and speech, while those in the arms in legs, can cause swelling and heaviness.

Macrocystic lymphatic malformations can be treated by either sclerotherapy or surgical removal. Sclerosants that are commonly used for lymphatic malformations include Doxycycline, OK-432, and Bleomycin. Alcohol, Sodium Tetradecyl Sulfate, Sodium Morrhuate and Acetic acid can also be used. Microcystic lymphatic malformations, especially those with no visible cysts, are more difficult to treat, and generally require surgical removal or contouring.

Simple macrocystic lymphatic malformations (cystic hygromas) can be treated very effectively and usually do not 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 of the swelling and inflammation.