A Canadian woman has said she was "getting ready to die" after doctors found a grapefruit-sized lump in her liver – only to discover the mass wasn't a cancerous lump, but something far less likely.

Cassidy Armstrong was diagnosed with a rare type of liver cancer after doctors found the lump following years of pain on the right side of her abdomen.

Ms Armstrong had began to experience a dull ache in her liver area, while also losing 11kg, becoming anaemic, and having digestive and sleep issues.

Doctors told her she had fibrolamellar carcinoma and the prognosis wasn't good; with the 36-year-old told she would only live for a few years.


"I was getting ready for the worst. I was getting ready to die," Ms Armstrong told US breakfast show Today.

But when the mass was removed, doctors made a shocking discovering – the lump was actually a rare parasite which had probably been growing inside Ms Armstrong for a decade.

"I wasn't sure what to think. I asked them, 'Is this good?' and they said, 'It's much better than what we thought you had,'" she said.

While Ms Armstrong didn't have terminal cancer, the diagnosis meant she would have to take an anti-parasite drug for the rest of her life.

Ms Armstrong was diagnosed with alveolar echinococcosis, a rare disease caused by the tapeworm echinococcus multilocularis.

People can get the tapeworm by eating infected meat or petting a dog and not washing their hands – but Ms Armstrong said she hasn't owned a dog since she was a kid.

"I have mixed feelings about it. I'm happy. I like being alive," she said of the diagnosis. "Psychologically, it's been really tough. I'm grateful and I'm happy that it's not what they thought it was. But it's been very hard."

According to The Conversation, echinococcus multilocularis usually only occurs in domestic dogs and cats, however, human cases in North America and Europe are slowly increasing.


The tapeworm can lead to alveolar echinococcosis, a disease which causes tumour-like cysts to form in organs.

The suspected cancer turned out to be a cyst caused by a tapeworm the 36-year-old had for at least a decade. Photo / Supplied
The suspected cancer turned out to be a cyst caused by a tapeworm the 36-year-old had for at least a decade. Photo / Supplied

The cysts can spread and be fatal if undetected.

University of Alberta professor of medicine Stan Houston told Today that alveolar echinococcosis is a "new problem" in North America.

There have been 15 cases of the parasitic disease in the Canadian province of Alberta since 2013.

Dr Houston said in countries like Canada where alveolar echinococcosis is still rare it can be easily mistaken for cancer.

"Nobody (here) has ever seen this before, nobody is familiar with it," he said. "So when you see a nasty shadow on the imaging, the ultrasound or MRI, all their experience would suggest it must be cancer."


Last month it was revealed that a man who went to his doctor after suffering from intense headaches actually had a tapeworm curled up inside his brain.

Gerardo Moctezuma went to doctors in the US state of Texas after experiencing severe pain in his head.

"It's very intense, very strong because it made me sweat, too – sweat from the pain," Mr Moctezuma told NBC News. "I would vomit from the pain."

After Mr Moctezuma sought medical help at Dell Seton Medical Centre in Elgin, Texas, neurosurgeons took an MRI scan of his brain, revealing the cause.

Mr Moctezuma had a tapeworm curled up in his brain which doctors believe could have been growing inside his head for years.

The man thinks the tapeworm may have come from some undercooked pork he ate in Mexico a decade ago. Mr Moctezuma said his sister had also had a tapeworm removed from her brain.

Dr Jordan Amadio told NBC News Mr Moctezuma's tapeworm case was "rare and truly extraordinary".

"In this patient's case he had been in the states from Mexico for over a decade. We actually think this had been growing in his brain for over a decade undetected," he said.