But just three days after her 28th birthday, Anderson went in to have the lump examined, and a week later she heard the news -- she had been diagnosed with breast cancer.
"It was normal, I noticed a lump at home, and I went in and got [it] checked," Anderson said. "During the week it takes for them to figure out what was going on, people kept telling me I'd be fine and that girls my age get benign lumps all the time and don't worry about it. But then we got the bad news."
Anderson then underwent two rounds of chemotherapy before undergoing a double mastectomy and reconstruction on April 9. The cancer is now gone and she's used her position as a Ph.D. student studying microbiology and cancer biology at the University of Minnesota to help promote awareness for breast cancer.
Anderson was recognized by the Twins in a special pregame ceremony before their game against the Blue Jays on Sunday at Target Field. She also threw out the honorary first pitch and received tickets to the game in Justin Morneau's suite.
"I'm very excited," Anderson said. "I had no idea I even had the potential to win, so when I got the email and the call that said, 'You get to go throw out the first pitch,' it was kind of overwhelming."
Anderson has more than done her part to promote breast cancer awareness since being diagnosed with the disease last September.
Anderson is part of a support group for young people who are breast cancer survivors and is keeping a public Caring Bridge blog and writing guest entries for the "Women of Strength" cancer survivor Web site.
Anderson also formed a team to raise money in the Tubbs Romp to Stomp out Breast Cancer Snowshoe Event at the University of Minnesota. And she applied to become a consumer reviewer on a federal Breast Cancer Research Review Panel, which awards government funding for breast cancer research to scientists across the country.
Anderson's story serves as an inspiration to many, and she is one of 30 Honorary Bat Girls, one for each MLB club. Each winner was selected by a panel that included MLB Players and celebrities in addition to fan votes cast on HonoraryBatGirl.com.
On Mother's Day on Sunday, hundreds of MLB players used pink bats by Louisville Slugger, the official bat of Major League Baseball, stamped with the MLB breast cancer awareness logo. The Honorary Bat Girl Contest was introduced in 2009 to raise additional awareness and support for the annual Going to Bat Against Breast Cancer initiative celebrated on Mother's Day.
"I think it's fantastic," Anderson said. "It's amazing to promote awareness. When I was going through the whole process, it was scary to think that maybe 20 years ago I might not have survived. But I'm completely recovered and have no disease left and it's all due to funding, fundraising and support and research and getting the word out."