It's Not a Tumor, It's a Brain Worm

Nov. 24, 2008— -- Late last summer, Rosemary Alvarez of Phoenix thought she had a brain tumor. But on the operating table her doctor discovered something even more unsightly -- a parasitic worm eating her brain.

Alvarez, 37, was first referred to the Barrow Neurological Institute at St. Joseph's Hospital and Medical Center in Phoenix with balance problems, difficulty swallowing and numbness in her left arm.

An MRI scan revealed a foreign growth at her brain stem that looked just like a brain tumor to Dr. Peter Nakaji, a neurosurgeon at the Barrow Neurological Institute.

"Ones like this that are down in the brain stem are hard to pick out," said Nakaji. "And she was deteriorating rather quickly, so she needed it out."

Yet at a key moment during the operation to remove the fingernail-sized tumor, Nakaji, instead, found a parasite living in her brain, a tapeworm called Taenia solium, to be precise.

"I was actually quite pleased," said Nakaji. "As neurosurgeons, we see a lot of bad things and have to deliver a lot of bad news."

When Alvarez awoke, she heard the good news that she was tumor-free and she would make a full recovery. But she also heard the disturbing news of how the worm got there in the first place.

Nakaji said someone, somewhere, had served her food that was tainted with the feces of a person infected with the pork tapeworm parasite.

"It wasn't that she had poor hygiene, she was just a victim," said Nakaji.

"We've got a lot more of cases of this in the United States now," said Raymond Kuhn, professor of biology and an expert on parasites at Wake Forest University in Winston-Salem, N.C. "Upwards of 20 percent of neurology offices in California have seen it."

The pork tapeworm has plagued people for thousands of years. The parasite, known as cysticercosis, lives in pork tissue, and is likely the reason why Jewish and Muslim dietary laws ban pork.

Kuhn said whether you get a tapeworm in the intestine, or a worm burrowing into your brain can depend on how you consumed the parasite.