Dr. Jonathan Rasouli says he was thrilled to tell his patient that she had a baby tapeworm living in her brain for a more than a year.
That's because up until that point, the team at Mount Sinai hospital in New York City believed that Rachel Palma had a deadly brain tumour.
"You would think that something like this, someone would react in shock and horror," Rasouli, the hospital's chief resident of neurosurgery, told As It Happens host Carol Off.
"But once we realized what we were dealing with, the reaction was actually one of joy and excitement."
The removal of the tiny parasite marked the conclusion of a more than year-long ordeal for Palma, a 42-year-old newlywed from Middletown, N.Y.
She first went to the doctor in January 2018 with a laundry list of neurological symptoms, she told the Washington Post.
She couldn't sleep, and when she did, she had nightmares. She was hallucinating. She had trouble talking. She kept dropping things. Her right hand and the right side of her face were numb.
An MRI scan revealed a lesion in the frontal left lobe of her brain. That, combined with her symptoms, led doctors to conclude she had a brain tumour.
The only thing left to do was open up her skull and determine whether it was malignant or benign.
"And you can just imagine, getting the news that, you know, your symptoms may be due to a brain tumour, it was just devastating to her," Rasouli said. "It was definitely a tough pill to swallow."
When Palma underwent brain surgery in September, she and her doctors steeled themselves for the worst news.
But as they were dissecting the brain tissue to reach the lesion, Rasouli says they found something "unlike any brain tumour we have ever seen before."
"It was virtually the same size, same shape and same firmness as a quail egg that you would buy in a store," Rasouli said. "And once we cut into it, a baby tapeworm came out."
Neither the doctors nor Palma know how she got the parasite, which is called Taenia solium and is extremely uncommon in North America.
Some people get it by ingesting microscoptic tapeworm eggs found in raw or undercooked pork, or unwashed fruits and vegetables from overseas. But Palma has never travelled outside the U.S.
People with adult tapeworms in their guts can also spread the parasite if the eggs are passed through their stool and they don't properly wash their hands.
"These these larvae or eggs can hatch and they can essentially migrate their way all throughout the body. Sometimes they can develop into a large adult tapeworm in your colon," Rasouli said.
"And in other cases, which is frequently rare, they can migrate their way through the bloodstream and essentially try to develop into more adult forms all throughout the body — and because the brain has such a robust blood supply, one of the favourite places for that baby to go is the brain."
Regardless of how it got there, the unwanted passenger has now been extracted, and Palma is in the clear.
It was bizarre, but happy news to deliver to a patient, Rasouli said.
"Her eyes went wide and she couldn't believe it," he said. "But as you can imagine, she was very, very happy to hear that she did not have cancer."
Palma told ABC Newsthat she's just happy to get back to normal.
"There is not a doubt in my mind that they saved my life," she said. "And they gave me my life back."
Written by Sheena Goodyear. Interview with Dr. Jonathan Rasouli produced by Allie Jaynes.