
She took birth control for acne. It fed a hidden cancer
Updated October 28, 2026, 9:51 a.m. ET
Most people aren’t grateful for their acne, but for Claudia Pereira, it was a “blessing in disguise.”
After struggling with blemishes as an adult, she decided to start birth control at age 37 to try to reduce them. Little did she know that this would lead to the discovery of hidden cancer in her uterus.
After starting to take the pills, Pereira began to bleed. And it didn’t stop – for months.
She was used to having her periods regularly, so the incessant bleeding set off alarm bells. Her prescriber said it might take a few months for her body to get used to the new medication. So she waited.
After four and five months of continuous bleeding, Pereira’s worries began again.
“I was like, ‘OK, is this normal?’ It was too much. I became anemic after six months,” she told USA TODAY.
Then the bleeding turned into a thick discharge which added to her worry, so she went to the emergency room. From there, she was transferred to a hospital for imaging. A series of tests, including a transvaginal ultrasound and an MRI, revealed a 7-centimeter mass.
While Pereira and her care team hoped the mass was a benign fibroid — a common noncancerous tumor — pathology revealed it was something much worse: uterine leiomyosarcoma, a rare cancer that grew in the smooth muscles of her uterus.
Pereira was shocked.
“I panicked. I froze. I started thinking about chemo, about work, about my life, about what was going to happen,” she remembers feeling after learning of the diagnosis. “It was terrifying. I went from thinking it was a common gynecological problem to learning it was a rare form of cancer.”

What is uterine leiomyosarcoma?
Uterine leiomyosarcoma is a type of cancer that develops in the muscular layer of the uterus, explains the Mayo Clinic.
Sarcomas, a type of cancer that develops in the bones or soft tissues of the body, are rare — they make up only 1 percent of all cancers, said Dr. Gina D’Amato, a medical oncologist specializing in sarcomas at the Sylvester Comprehensive Cancer Center, part of the University of Miami Health System, who helped treat Pereira.
Uterine sarcomas themselves are rare and account for about 5% of all uterine cancers, according to the American Cancer Society.
Given that Pereira was younger than 50 at the time of his diagnosis, his case was even more unusual, D’Amato told USA TODAY.
“Most uterine sarcomas occur in people over the age of 40. The average age at diagnosis is approximately 60,” notes the American Cancer Society.
Like some breast cancers, uterine leiomyosarcoma may have estrogen or progesterone receptors, which can cause the cancer to grow in the presence of these hormones.

Pereira’s tumors tested positive for these receptors, which is why starting birth control likely triggered the severe symptoms she experienced.
The estrogen released during Pereira’s regular cycle could have already been “feeding” the cancer, D’Amato explained, and then “growing really quickly” when the additional hormones were added to the drug.
“In her case, she didn’t take (birth control) for a very long time. I think she was lucky, so to speak, in the sense that it may have allowed (the cancer) to grow and be discovered,” D’Amato added.
More research is needed to better understand this type of cancer.
“Thank God for Acne”
Pereira’s mass was removed and scans showed no evidence the disease had spread elsewhere in his body. For further reassurance, Pereira underwent a hysterectomy in which her uterus, cervix and fallopian tubes were removed.
After all those organs were sent to pathology, “everything came back clean, so that was another worry (gone),” she said. “I was very relieved.”
Pereira was lucky. Given the size of the tumor, D’Amato said she was at “high risk of it spreading.”
If the tumor had been discovered six months to a year later, the situation could have been “much worse” without such a positive outcome, D’Amato added.

In July, Pereira celebrated a cancer-free year. And she’s making the most of it, from traveling to Bali for her birthday to spending time at home with her family, who she calls her “strong support system” that made all the difference in her trip.
“I got a second chance at life, and I’ve been living harder ever since,” she said.
She hopes sharing her story will help raise awareness of this rare cancer and inspire others to listen to their bodies and advocate for themselves.

“Be brave. Don’t overthink it,” she told those who might have trouble talking about their health. “Don’t hesitate. Listen to your body. Your body will always tell you when something is wrong. I am living proof.”
D’Amato also encourages patients to listen to their body and know their family history. Additionally, when starting treatment, she encourages patients to conduct close monitoring, under the guidance of a physician.
“If a doctor prescribes you a medication, you want to make sure you follow up with that doctor, I would say within a month,” suggests D’Amato, to discuss potential side effects.
Pereira remains grateful for those little bumps on her face: “Thank God for the acne.”
“Who knows how long (the cancer) had been there. If I hadn’t been on birth control, I would never have known,” she said.
Gn Health