When volleyball star Addison Rowan felt an unusual lump in her breast at 11 years old, her doctors dismissed it as a sign of puberty.

Over the next five years, that pea-sized mass grew to about the size of a ping-pong ball, at which point she was referred for tests.

Addison was assured 'it wasn't a huge concern' and that it had a less than one in 100 chance of being breast cancer because of her age and lack of family history.

That is when they found out it wasn't breast cancer, but a ultra-rare cancerous tumor that, if not caught early, kills four in 10 children.

The North Carolinan teenager was diagnosed with alveolar soft part sarcoma in September 2021 at age 16.

It forms in the soft tissue that forms in between fat, muscles, and nerves. It only strikes about 80 Americans per year. 

It normally starts in the arms of legs. Doctors believe Ms Rowan is only the second reported case of the ASPS forming in the breast, and that previous case was in an older woman. 

The high school junior learned about her diagnosis after returning home to find her parents crying. 

Ms Rowan, now 19, told People: 'I immediately started freaking out. I just froze. I probably didn't speak for 20 minutes. I was just so shocked.' 

Ms Rowan was immediately scheduled for surgery. That same week, her volleyball hosted a sold-out game to help support her. 

She said: 'It was probably the best volleyball game I played in my whole entire life. I was just trying to give it my all because I literally didn't know if I was going to ever be able to play again.

'My whole team was rallying around me, and they dedicated the game to me.' 

The team won the game.

During a six-hour surgery three days later, doctors discovered that Ms Rowan's cancer had spread to the surrounding tissue in her breast and around her ribs. 

Surgeons took tissue from the skin on her back to reconstruct her breast, and they were forced to collapse one of her lungs and remove a rib. 

Ms Rowan said: 'When I woke up, I was in so much pain. I didn't even know that there was pain that was that bad.

'I was extremely scared because I had never felt that kind of pain before. I literally kept asking my parents. I was like, "Am I going to be okay? Am I going to make it?"'

Soft tissue sarcomas make up just one in 100 cancers in the US, and ASPS cases account for as few as one in 500 of those. 

If the cancer has not spread, the survival rate after five years is just over 90 percent. Even in cases where the disease has spread, children have a 60 percent survival rate. 

Doctors were able to remove all of Ms Rowan's cancer, and this month, the college sophomore celebrates her third anniversary of being cancer free. 

She said: I learned I was definitely stronger than I thought I was. I pulled out the strongest version of myself. That's what helped me defeat the odds.'

She is even able to play club volleyball at her university now that her body 'is pretty much back to normal.' 'I honestly feel stronger than I was before,' she said.

Ms Rowan is majoring in biology and hopes to study oncology or pathology to 'learn more and help people.' 

She said: 'No matter what the odds are, how rare a condition is that you have, at the end of the day, you are in control of your story and your future.

'When you feel like everything's stacked against you, don’t let that defeat you and define you. You can push yourself and change your future.'