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. "We were amazed when we found this new type of disease — tapeworms growing inside a person, essentially getting cancer, that spreads to the person, causing tumors," said study researcher Dr. Atis Muehlenbachs, a staff pathologist at the Centers for Disease Control and Prevention's Infectious Diseases Pathology Branch (IDPB). http://www.livescience.com/52695-tapeworm-cancer.html?cmpid=514645
I can now peacefully go to sleep for the night. Seriously though, I hope I don't have dreams about this.