When you go to the doctor, you expect them to diagnose you properly. So when British teen Melissa Sutton went to the doctor for a sports injury and was diagnosed with a pulled muscle, she thought everything would be fine.

Everything wasn’t fine, however. The 16-year-old, from Rochdale, UK, had pain in her lower rib cage and shortness of breath, but every time she went to the doctor it was the same story — nothing but a pulled muscle. It wasn’t until her mother rushed her to the ER that the real cause of her pain and discomfort was revealed: It was Ewing sarcoma, a rare type of bone cancer.

“We felt like our world had been turned upside down when we were given the diagnosis,” Alison Brookes, Melissa’s mom, told news.com.au. “For months we knew something was wrong, but we weren’t listened to. We were just fobbed off.”

Ewing sarcoma is a tumor that forms in the bone or soft tissue and is common in teens and children. The survival rate of the cancer for children under 15 is 76 percent, while the survival rate for teens 15 to 19 is 60 percent.

“When I was diagnosed with cancer it was a huge shock. It was news that no teenage girl wants to hear, Sutton said. “The treatment has made me [feel] very poorly, but I am just glad the cancer was detected when it was.”

She has had 12 rounds of chemotherapy since the cancer was found, with three more scheduled for later this year. By the time Sutton is done, she’ll have completed 30 rounds of radiotherapy altogether. Although she was initially concerned about losing her hair, she knows now that she is bald for a reason. “I want to raise awareness so that other people who experience the same symptoms don’t give up and trust their instincts,” Sutton said.

There hasn’t yet been any movement by the family against the doctor or doctors who diagnosed her initially, according to Raj Patel, medical director for NHS England in Greater Manchester and Lancashire. “Our priority is to ensure that patients receive the highest quality primary care services at all times. We have not yet received a complaint by Alison or her family, but should we do so, we will take the issue forward and investigate it thoroughly.”