When doctors at US’s Mount Sinai Hospital opened a woman’s skull, expecting to find a brain tumour, they were shocked to see a tapeworm instead. Rachael Palma was told by her doctors that there was a cancerous tumour growing in her brain. She was prepped for the surgery and wheeled into the operation theatre at the New York City hospital. But as soon as her skull was opened, the doctors were stunned to find a mass about the size and shape of an egg. When they removed it and sliced it open, they found a baby tapeworm. The news was bittersweet for the Palma, who was part relieved that the mass was not cancerous and partly disgusted with the thought of a parasite growing in her brain. This brings us to question how do tapeworms enter the human body.

What are Tapeworms?

Tapeworms are parasites that live inside the intestines of most animals. They are flat with segmented bodies. Tapeworms enter the human body through the oral route, when people eat undercooked meat that contains the larvae. Once inside, they attach themselves to the intestines of the animals, feeding off on the host’s nutrition.

How do Tapeworms Enter the Brain?

Tapeworms in the brain usually show up in MRI scans as whitish blobs and can be confused for tumours. These are the larvae of the worms that live as large cysts inside the brain in a condition known as neurocysticercosis.

Tapeworm eggs from the faeces of infected humans often end up in the soil. These eggs can find their way into pigs when they accidentally swallow it while rummaging for food. 100 Tapeworm Eggs Found in Eight-Year-Old's Gurugram Girl's Brain! Suffered from Epileptic Seizures and Headaches.

When the eggs reach their stomach, they hatch and burrow into the pigs’ bloodstream. They latch onto the blood vessels in the animals’ muscles, which are then eaten as pork by humans.

When the pork is undercooked, the larvae survive the heat and enter the human intestines. Once the tapeworm finds its way into your body, they are free to travel. From there, they follow the same process as they would in a pig and lodge themselves in the human blood vessels.

After the stomach, the common places where they settle include the eyes and the brain.

They form cysts around themselves to hide from the immune attacks. These cysts often act like tumours, putting pressure on various areas of the brain and causing seizures and convulsions. Doctor Removes Three-Inch-Long Live Worm From Six-Year-Old's Nose in Vietnam, Video Goes Viral.

These cysts can also rupture, spilling its contents into the brain and causing meningitis. They can also cause headaches, personality changes and mental impairment.

How Are Tapeworms in the Brain Removed?

Treatment for tapeworms in the brain can sometimes trigger the response that the cysts themselves may cause – inflammation. When the cysts are destroyed with drugs like praziquantel, the body triggers its inflammatory response, causing swelling in the brain.

Prevention is the best way to deal with neurocysticercosis. World Health Organization suggests multiple measures such as mass drug administration, health education, improving hygiene, encouraging food safety, improving pig husbandry, vaccinating pigs and enforcing strict inspection of meat products.

(The above story first appeared on LatestLY on Jun 10, 2019 01:13 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).