Tapeworm Spreads Deadly Cancer to Human

A parasite with cancer infected a man, and the tumor cells jumped across the species line

By Rachael Rettner, LiveScience on November 5, 2015

Three adult Hymenolepis nana tapeworms. Credit: CDC/Wikimedia Commons

A Colombian man's lung tumors turned out to have an extremely unusual cause: The rapidly growing masses weren't actually made of human cells, but were from a tapeworm living inside him, according to a report of the case.

This is the first known report of a person becoming sick from cancer cells that developed in a parasite, the researchers said.