Stanford researchers may have discovered a drug for a rare and often untreatable disease that leaves children with massive, and sometimes deadly, growths on their faces, necks and other parts of their bodies.

Here's the twist: The drug is Viagra.

In very early reports, sildenafil - best known under the brand name Viagra and sold as a treatment for erectile dysfunction - reduced the size of growths in three children with lymphatic malformation, a disease that causes spongy cysts to swell and clog up the lymphatic system.

It's too soon to say how effective Viagra could be in treating most cases of lymphatic malformation, but Stanford researchers are starting a clinical trial and currently seeking patients to test the drug.

"Some of these kids have no other hope," said Dr. Al Lane, a pediatric dermatologist at Packard Children's Hospital at Stanford. "The first child we treated, the malformation was so big and she was in such bad shape that there was nothing we could do for her. We gave her the sildenafil, and we were blown away."

Lane stumbled upon Viagra as a possible treatment for that child, a 5-month-old girl, by accident.

Blood pressure treatment

Sildenafil was first developed in the early 1990s to treat high blood pressure, but early clinical trials found that it was more useful in treating erectile dysfunction. Today, sildenafil is sold primarily under the name Viagra for erectile dysfunction, although it's also used under the name Revatio to treat a rare form of high blood pressure involving the lungs.

About a year ago, Lane examined the infant girl, who had severe lymphatic malformation with growths that had swelled up in her chest and wrapped around her aorta. The pressure caused high blood pressure and, eventually, heart failure, so Lane gave her sildenafil.

The drug helped her heart problems - but Lane also noticed a massive reduction in the lymphatic malformation. Intrigued, he tried the drug on two other patients with lymphatic malformation and noticed similar results. One patient had a roughly 25 percent reduction in a growth that obstructed his vision, and another patient had a roughly 75 percent reduction in growths on her back.

Lane wrote up his findings in a short letter published in the New England Journal of Medicine last month. Since then, a fourth patient has been treated and also saw some improvement. In all four cases, the growths started to come back when the children were taken off sildenafil, and the parents opted to resume drug treatment.

Lymphatic malformation affects the lymphatic system, which is part of the circulatory system. The lymphatic system removes excess fluid from tissues and organs, and transports white blood cells. In patients with lymphatic malformation, the vessels that make up the system become clogged, and fluid builds up and creates large cysts or masses of spongelike tissue.

The disease mostly affects children, who are usually born with it, but it's possible for older youngsters and adults to develop malformations, too. Scientists don't know what causes lymphatic malformation, and there's currently no way to prevent it or cure it.

Organs can be affected

Occasionally, the growths will disappear on their own after a few years, but many patients have them permanently. The growths are sometimes purely cosmetic, but they can also put pressure on internal organs, the eyes, the tongue and the throat, and lead to major complications including blindness, breathing problems and heart failure.

The growths are typically treated by either surgically removing them or by injecting a drug that causes the affected lymphatic vessels to shrink and collapse. But those treatments aren't effective for all types of lymphatic malformations.

Lane isn't sure why sildenafil seems to work. The drug treats erectile dysfunction by smoothing and relaxing the muscles that make up blood vessels in the penis, allowing them to dilate and increase blood flow. It's possible that it also affects the muscles that line some lymphatic vessels, relaxing them and improving circulation in areas that have become clogged.

Other physicians who treat lymphatic malformation say Lane's work is intriguing, but not yet cause for major celebration. With only four patients treated so far, it's too early to say just how effective sildenafil is, said Dr. Jonathan Perkins, an expert in vascular anomalies who treats children with lymphatic malformation at Seattle Children's Hospital.

"Honestly, I don't know what to make of this just yet," Perkins said. "Is the drug safe? What does Viagra do to little kids? This is very interesting, and it needs further study."

But he's hopeful that the drug will give doctors one more option for treating difficult cases, or perhaps make surgeries and other treatments safer and more effective.

That's the appeal of the drug for parent Jean Arnold of San Francisco. Her 3-year-old daughter, Olivia, has a lymphatic malformation on her face that makes her look like "a chipmunk," Arnold said. Olivia is lucky in many ways because her malformation is mostly cosmetic, but she's had one major surgery already, and may have another one soon.

"We know it will ultimately affect her if we're not able to resolve it for her aesthetically," Arnold said.