A Perth mother says her shocking cancer diagnosis was a ‘chance’ decision as doctors searched for the cause of her leg and back pain.

Jenelle Holthouse, 48, first noticed something was wrong while exercising in March and went to her doctor to figure out exactly what the problem was.

The mother of six children aged 11 to 24 underwent a CT scan because she suspected she had a pinched nerve in her back.

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Instead, scans revealed something much more serious: a lump in her kidney.

“It was just a coincidence, otherwise it wouldn’t have been found,” Holthouse told 7NEWS.com.au.

“It was devastating. You go there thinking you’ve bruised a nerve, but then you’re told it’s cancer.”

Holthouse was told she had renal cell carcinoma, the seventh most common cancer in Australia.

“I’m lucky, not so much because I have it, but because of the way I found it,” she said.

“The doctor could have easily dismissed me, but I was lucky that I was referred for more tests and that it was discovered relatively early.”

She will be admitted to Fiona Stanley Hospital on Monday, where surgeons will remove the 3.2cm mass.

She then has to play a “waiting game” to find out if the procedure was successful and what other medical interventions are needed.

“I hope it goes well and that it will be about recovery, rather than more treatments,” she said.

She will be tested every few months to check for a return of the disease.

Symptoms of kidney cancer include blood in the urine, persistent fatigue, fever not caused by a cold or flu, rapid and unexplained weight loss, and a dull ache in the side or lower back.

Her back pain was the reason she initially went to the doctor, but otherwise Holthouse felt fairly healthy until she recently started experiencing fatigue.

She has also put her career on hold while she undergoes treatment.

“Our mother, a senior care worker who spends all her time caring for others and offering her love and care where needed, had to stop working,” her daughter Abbie said in a GoFundMe to help with bills and groceries.

“Life doesn’t stop when you’re diagnosed with cancer and it certainly doesn’t stop for a mother who’s still caring for her two youngest children – one of whom is still in elementary school – while trying to juggle paying bills, groceries and the high costs that come with living in today’s economy.”

Holthouse is “overwhelmed” by the generous donations as she works to get her health back on track. “I didn’t expect this at all,” she says.

She also told others to push for more medical testing if they felt like something was wrong with their bodies.

According to the Cancer Council, kidney cancer symptoms “can occur with other illnesses,” so you should see your doctor if you have any concerns.