Cystic hygroma (CH) or lymphangioma is a fairly rare malfunction of the lymphatic system. Children can be born with this, and most parents discover it by the time their child is about two years old. It feels like a soft, fluid-filled lump under the skin, usually on the back of the neck, sometimes in the underarm area and less often in the groin or buttocks region. The lump consists of many small, fluid-filled sacs called cysts; it can be pictured as similar to a bunch of grapes.

Sometimes a CH stops growing or even shrinks a bit, then grows again; occasionally they bleed or become infected. Sometimes they grow very fast. In many cases, they are just bothersome cosmetically.

In some cases, if the CH is big enough, it can press into important tissues, such as the trachea (your child’s breathing tube) or the esophagus (the tube that goes to your child’s stomach). When this happens, the doctor may have to remove some of the tumor to free up your child’s breathing or eating. Some children require a feeding tube or tracheotomy (a breathing tube).

Doctors can diagnose CH using X-rays, CAT scans or ultrasounds, depending on the location of the growth.

Doctors think CH is caused by a failure of the lymph system to hook up to the circulatory or venous system while the baby is developing in the womb.

For some types of cystic hygromas, the doctor can inject a fluid into the cyst. This is done a few times over a period of weeks, depending on the size of the cyst. This fluid is called OK432. It irritates the cyst tissue and dissolves it. So at first, your child will experience redness and some swelling. If used on the right type of CH, the effective rate is high.

Other, less common treatments include chemotherapy, radiation or steroids.

Depending on the type of cysts present, the doctor may recommend surgery. The doctor will remove as much of the CH as possible (or all of it, if this can be done). If the doctor can reach all of the cysts, the chances are excellent that your child will never have this problem again. If not (sometimes this happens because it’s growing too close to important structures), then the chance of it re-growing is fairly high.

As with any surgery, there are risks of bleeding and infection as well as recurrence or damage to structures close to the CH.

For an appointment with a Washington University pediatric surgeon, call (314) 454-6022, Monday-Friday, 8 a.m.-5 p.m.