Woman Relieved After Suspected Brain Tumor Turns Out to Be Tapeworm Egg

Above, the egg from a member of the Taenia family of tapeworms.
Above, the egg from a member of the Taenia family of tapeworms.
Image: CDC

You wouldn’t expect that finding a tapeworm egg in your brain would be seen as good news, but such was the case for New York resident Rachel Palma this past fall. That’s because the larva found inside was the true cause of Palma’s worsening symptoms of insomnia and hallucinations, rather than a brain tumor that her doctors initially suspected. Once the egg was removed, though, her health recovered.


Palma’s story, reported by the Washington Post on Thursday, has all the markings of a tale you’d find in a particularly gruesome children’s horror anthology.

What started as trouble sleeping for Palma, either through insomnia or nightmares, progressed into waking hallucinations. By January last year, she became increasingly disoriented and unable to remember things. Eventually seeking care at New York’s Mount Sinai Hospital, doctors initially diagnosed Palma with brain cancer, after spotting a lesion on her MRI scan. But when they performed surgery on her last September to remove the supposed tumor, they instead found a ball-shaped mucus-colored cyst. And once they cracked open the cyst, they found a tapeworm larva.

“We were all saying, ‘What is this?’ ” Jonathan Rasouli, chief neurosurgery resident at the Icahn School of Medicine at Mount Sinai, told the Washington Post. “It was very shocking. We were scratching our heads, surprised at what it looked like.”

Palma’s true malady was something called neurocysticercosis, a rare, complicated brain infection caused by the pork tapeworm, or Taenia solium.

There are two ways this worm can make us physically sick. We can catch an infection from undercooked pork contaminated with tapeworm cysts containing larvae; the cysts travel into our small intestine, where they fully mature into up to 25-foot-long adults, mate, and seed our poop with a new batch of eggs. These infections can cause usually mild gastrointestinal symptoms like stomach pain, diarrhea, and weight loss, though many people might never feel anything.

But human hosts can also be a dead end for the worm’s life cycle. The new eggs need to find their way back into pigs to repeat the steps above, or they’ll never become adults. If another person gets infected by them instead, such as through eating food handled by someone who didn’t wash their poo-ridden hands, the eggs will grow into their cyst-covered form but then be stuck there forever. For an added twist of dark humor, you can also re-infect yourself with the stunted tapeworm eggs you helped bring into the world.


This arrested development can still be dangerous for us, since the cysts can end up in the bloodstream via the gut and travel to the brain or other vulnerable regions. From there, the larvae—usually after dying—can trigger a massive immune reaction that damages surrounding tissue. But these complications can take years to show up after the initial infection.

Compared to the grim prognosis for most brain cancers, neurocysticercosis is usually much more manageable if detected early, though treatment can vary based on where and how many cysts are found. Still, according to the Centers for Disease Control and Prevention, up to 10 percent of people hospitalized for it die. In Palma’s case, fortunately, after the doctors removed the tapeworm, her symptoms largely disappeared.


“The best part of my story is it has a happy ending,” she told the Post.

Though neurocysticercosis is relatively rare in the U.S., it’s the most commonly reported brain worm infection in endemic areas like Latin America, Africa, and Asia, as well as a common cause of seizure. And cysticercosis in general is considered one of five neglected parasitic infections by the CDC, meaning that it warrants more public health attention in the U.S. as well.


Born and raised in NYC, Ed covers public health, disease, and weird animal science for Gizmodo. He has previously reported for the Atlantic, Vice, Pacific Standard, and Undark Magazine.



“relieved” it’s only a tapeworm egg