Doctors told a 16-year-old that her aches were growing pains and suggested she lose weight. She had bone cancer.

• Reanna Tillman was diagnosed with bone cancer a week before her 17th birthday.
• She had tumors removed from her leg and shoulder, and now the cancer is in her spine.

At age 16, Reanna Tillman started experiencing leg pain so severe that she said she wanted to chop off her limb.

Tillman, now 23, told Insider that her leg would give out seemingly out of nowhere, causing her to collapse on the ground. Months into her year of pain, she had to start homeschooling because it hurt too much to walk around her high school campus.

When she sought medical care, she said the emergency room doctors told her it was probably growing pains causing her discomfort. One primary care doctor even suggested that she lose weight to reduce the strain on her legs, Tillman said.

Those doctors changed their tone once Tillman was able to get an MRI scan, which revealed a sizable tumor in her leg. She was diagnosed with osteosarcoma, the most common type of bone cancer, and quickly got surgery on her leg followed by several cycles of chemotherapy.

However, between rounds of chemo and radiation, she said she experienced a "medical miracle" — a healthy baby girl, also named Reanna, who was delivered via C-section on January 1, 2021.

The tumor in her leg was just the start of Tillman's cancer story. She said she had multiple tumors in her shoulder, which resulted in a donor bone transplant that later became infected. Now, she has three tumors growing in or around her spine and is paralyzed from the chest down.

Doctors said she is terminal, and she's making the most of the time she has left.

She was diagnosed with osteosarcoma a week before her 17th birthday

Tillman said when she first learned she had cancer, the doctor told her she either had osteosarcoma or Ewing's sarcoma, another type of cancer that affects the bones — and the only way to treat it was to amputate her leg.

At another hospital, a second doctor confirmed that the tumor in her leg was an osteosarcoma, but said he could remove the affected bone while saving the leg. Tillman said the doctor performed a leg salvage surgery, where an orthopedic surgeon removed the tumor in her leg without removing the whole limb.

She said the surgeon cut out part of her femur and knee, and replaced the bone with metal. After that, she went straight into chemotherapy to ensure her leg was cancer-free. She got about eight rounds of methotrexate, a drug used to slow the growth of cancer cells, which she said made her nauseous.

In March 2017, Tillman was cleared to return to school. She finished high school and went straight to college that summer, where she was eager to get on with her life.

But in the middle of summer session — a year after her initial diagnosis — Tillman's cancer came back, this time in her shoulder.

"I started crying because I was just starting to feel normal, and here we go again," she said. "To this day, I feel like every time it's good, here it comes."

She needed her knee, thigh bone, and shoulder blade replaced

At her annual checkup in 2017, Tillman said her doctors found a tumor in her shoulder blade. They quickly removed the tumor and replaced the top half of the scapula. But the cancer came back again, which meant she needed the whole scapula replaced with a donor bone.

That bone transplant would eventually cause her more pain; in March 2022, the donor bone died.

"It was leaking, it was eating through my skin," she said. "They had to remove the donor bone completely and shaved down my clavicle — to clean out the infection most importantly, but then to attach it to my arm."

Now, Tillman's right arm is attached to her collarbone. Doctors had to remove the entire shoulder blade and some of the muscle around it, so she said she can no longer rotate her shoulder or move her arm backwards.

She said she lost even more mobility about six months later, when a tumor on her spine paralyzed her from the chest down. She had been aware of the tumor since 2018 and received radiation to slow its growth, but it finally caught up to her this October.

Amid the cancer relapses, she had a 'medical miracle'

After finishing radiation in 2019, Tillman said she decided to live a little bit. She said she finally felt normal, "great" even, and fell in love with her child's father.

During those happy years, the tumor in her spine was growing insidiously. When she went to the doctor for back pain in 2020, she said they told her the cancer was just centimeters away from crushing her spinal cord.

About a month after she learned she could be paralyzed any day, Tillman found out she was unexpectedly pregnant for the first time.

She miscarried the first pregnancy, which still stung despite the odds. But she got pregnant again during lockdown, "and this time, she stuck," Tilllman said.

Tillman calls her daughter a "medical miracle," sometimes Tinkerbell or Tink for short. But the baby's given name is Reanna, so her mother's memory will live on long after she's gone.