Silver Spring, MD (3/20/09)--Homework, friends, clothes, boys—all these normal teenage problems can be dwarfed by something the size of a nickel. Last October, when sophomore Katie Johnson* went in for a routine blood test, doctors discovered that she had a tumor on her pituitary gland, near the base of her brain.

"Initially, I was very concerned," says her mother, Mary Johnson.* "Being her mom, I was very upset and worried... There were a few weeks there that we weren’t sure what it was and what to do."

The pituitary gland, located under the brain’s hypothalamus, produces a hormone called prolactin, which is how doctors detected the problem. While a normal prolactin level is about 20, Johnson’s was at 333. She got an MRI and doctors discovered the growth from looking at the scans. The tumor was disrupting her hormones, and if it continued growing, she could lose her eyesight.

"At first it was weird because I didn’t feel like anything was wrong," she says. "I guess normal teenagers worry about the clothes they’re going to wear. But other people have to worry about how they’re going to survive the next day."

Though the family and doctors considered surgery to remove the tumor, they decided to use medicine to regulate prolactin levels. Johnson still takes half a pill every Monday and Friday and the treatment seems to be working. In her most recent MRI, taken in late February, the growth had shrunk and Johnson’s endocrinologist believes she may be able to stop taking the medicine in a few years if her prolactin levels remain low.

"Once we started getting more and more information, then it started to get less scary," says Mrs. Johnson. "It was pretty stressful, but…our pediatrician recommended two very, very good doctors."

One of those doctors was famed neurosurgeon Ben Carson, and Johnson was able to see one of his associates and even meet Dr. Carson at a book signing.

The ordeal has been a learning experience for Johnson. "I learned that it could be a lot worse," she says. "When I was in the hospital and I went to different doctors I could see people who…needed more help."

"I guess it was lucky that it wasn’t harmful and that I survived it," she adds. "It was cool to see that [I could] overcome something like that."

*names in this article have been changed