A mother of six from Coventry, U.K., said she's cancer-free after coughing up a three-quarter-inch tumor.

Claire Osborn, 37, was driving when she felt a tickle in her throat, the Daily Mail reported. Moments later, she hacked up a heart-shaped lump of liver-colored tissue.

"I knew something was very wrong so I went straight to my GP who sent the tissue sample away for tests," Osborn told the Daily Mail.

The tests revealed Osborn had metastatic adenocarcinoma - an aggressive form of cancer that likely stemmed from glandular tissue at the back of her mouth. Doctors told her she'd need chemotherapy to kill any remaining cancer and gave her 50-50 odds of surviving, Osborn said.  But when they ran a positron emission tomography (PET) scan to spot the cancer left behind, they found none.

"The consultant turned round to me and said, 'It appears you have coughed up your cancer. Congratulations,'" Osborn told the Daily Mail. "I was totally flabbergasted. I couldn't believe a coughing fit had saved my life."

Osborn had a small operation to remove any cancer cells that might have been lingering at the back of her mouth on Nov. 29, the Daily Mail reported.

Dr. Gary Walton, the head and neck surgeon who treated Osborn, said it's rare for patients to cough up cancer, but not impossible.

"We suspect the tumor grew on a stalk at the back of her mouth which is very difficult to detect," he told the Daily Mail. "Somehow she dislodged this and the stalk snapped and she coughed up the tumor."

Dr. Edward Kim, chief of head and neck medical oncology at MD Anderson Cancer Center in Houston, said the coughing fit acted as surgical resection of sorts. But he added that metastatic adenocarcinoma usually requires chemo and radiation treatment, too.

"It's very rare that these types of tumors don't require other treatments beyond surgery," he said.

As for the fluky fit that alerted Osborn to her cancer, Kim estimated fewer than 5 percent of patients discover mouth and throat tumors haphazardly.

"Usually there are subtler symptoms, like difficulty with swallowing or speech," he said.

Osborn said she's lucky to have coughed up the cancer before it invaded other parts of her body.

"If I hadn't coughed it up, the tumor would have grown and almost certainly spread to my other organs," she told the Daily Mail. "Anyone with a persistent cough should get checked out as a precaution."