WEDNESDAY, Jan. 25 (HealthDay News) -- A new preliminary report suggests that the active ingredient in Viagra, sildenafil, could reduce the size of large growths that can disfigure the bodies of children.

The findings could point to yet another use for the medicine, which was first developed as a heart medication until researchers noticed that it helped impotent men have erections. This time, researchers stumbled upon an alternate use while using a Viagra-like drug to treat a rare condition that causes high blood pressure in the arteries that lead to the lungs.

There are caveats: The treatment is very expensive, the research is only in its early stages, and the medication may not be a cure. Still, the research raises the prospect that "we could treat some of these little kids who have little or no hope," said report co-author Dr. Alfred Lane, a professor of dermatology and pediatrics at Stanford University School of Medicine.

The growths in question are known as severe lymphatic malformations. They appear in children, including babies, and create disfiguring growths of fluid and vessels.

The growths can be as big as a volleyball or a basketball, Lane said. They seem to appear when the lymphatic system, a component of the body's immune system, becomes clogged, although the exact cause isn't clear, he said.

In some cases, the growths can be dangerous, such as when they pose a risk of blocking an airway pressuring a nearby organ.

Surgery to remove the growth is one option, although it may not be possible, he said. For some children, "there's not a whole lot you can do about it."

That's where sildenafil may help.

Researchers used a form of the medication called Revatio to treat a baby girl who suffered from pulmonary hypertension, the condition that causes high blood pressure in certain arteries. The investigators found that the medication had another effect: it reduced the size of a lymphatic growth.

The child, who was severely ill, died. But researchers were curious about the effects of the drug, and they tried it on two other children. Their growths shrunk and became softer after 12 weeks.

The parents of the children decided to continue giving the drug to their kids; it's not clear how they're doing now, but Lane will see one of the patients soon.

The drug may not eliminate a growth, "but if it can reduce it to the size that they can remove it, that would be good," Lane said.

Revatio costs $800 to $1,000 a month, Lane said, although the Pfizer drug company is donating the drug for research purposes. While the dose is low, potential side effects include dizziness, eye problems, nosebleeds and nausea, Lane said.

Researchers don't know how the drug works to reduce the size of the growths, Lane noted, although one possibility is that it makes it easier for the lymph system to drain fluid.

A new study of the treatment is underway.

Dr. Richard Smith, a pediatric otolaryngologist who's familiar with the report, said it offers an "exciting and serendipitous finding." But it must still be validated to prove that it truly holds promise, said Smith, vice chair of the University of Iowa's department of otolaryngology -- head and neck surgery.

The report appears in the Jan. 26 issue of the New England Journal of Medicine.

More information

Children's Hospital Boston has details about lymphatic malformations.