Suspected brain cancer turns out to be pork tapeworm infestation

Doctors in Spain suspected that a man suffering from chronic headaches had brain cancer. A scan showed a number of poorly-defined lesions, typical of cancer that has spread from elsewhere in the body. But when they conducted a higher-resolution MRI, they found not tumors but the larvae of pork tapeworm, a parasitic infection.

Their report, "Autochthonous Neurocysticercosis Brain Lesions Mimicking Metastatic Disease," published in the U.S. Centers for Disease Control and Prevention journal Emerging Infectious Diseases, describes a lifelong resident of Castellón who sought care in 2025. He had never traveled abroad, but his medical team confirmed the diagnosis with a blood test specific to Taenia solium, the pork tapeworm.

Taenia solium is a tapeworm that lives in the human gut and sheds eggs in feces. People who swallow those eggs — typically through food or water contaminated with infected human waste — become accidental hosts. The eggs hatch, and the larvae burrow through the body and form fluid-filled cysts. When they settle in the brain, the condition is called neurocysticercosis. Eating undercooked pork is a well-known way to ingest an adult tapeworm, but the cystic brain infection comes from ingesting their eggs.

Identifying the parasite let the man avoid the brain biopsy that might otherwise have proven he did not have cancer; he was instead successfully treated with the antiparasitic drugs albendazole and praziquantel and released without complications.

According to wikipedia, neurocysticercosis is a leading cause of acquired epilepsy worldwide, but cases are rare in Europe but not unknown; a similar case surfaced in Germany in 2026.