In a medical first, a Colombian man died of cancerous tumors he developed from a tapeworm living in his body. The case baffled doctors in Colombia, who asked the U.S. Centers for Disease Control and Prevention (CDC) for help, Health Day reported.
In 2013, the 41-year-old man went to a hospital to have himself checked. He had HIV but stopped his medication a few months prior to the hospital visit. His immune system was weak, he had a fever and he had difficulty breathing. He also had dwarf tapeworm infestation.
After CT scans were conducted, the doctors saw tumors growing in the man's lungs, adrenal glands and liver. Dr. Atis Muehlenbachs, CDC pathologist and lead author of the report, said the growths looked like cancer but they were small.
"They were way too small to be human," Muehlenbachs told Health Day. "They were actually about 10 times smaller than a human cancer cell." And they looked like they were fusing together, something that human cancer cells don't do.
After DNA tests on the tumor cells, Muehlenbachs was surprised to discover that they were tapeworm cells.
"We knew invertebrates can grow tumors, but the fact that one can invade and disseminate in a human and make them sick just really, really defied belief," he told NPR. This was the first known case of cancer cells being transmitted from parasite to human host.
Unfortunately, three days after the discovery, the patient died of kidney failure. The tumors were not the direct cause of his death, but they contributed to the decline of his health.
The researchers have found no clear explanation for how the tapeworm cells caused the tumors in the man, although his weakened immune system could have contributed to the condition.
"We'd also like to know how common this is," Muehlenbachs said. "We think it's rare, but we don't know how rare."
Dwarf tapeworm, or Hymenolepis nana, is commonly found worldwide, particularly in developing countries. People usually get infected by ingesting food or water contaminated with feces that have dwarf tapeworm eggs. It is the only tapeworm capable of completely living and reproducing in the human gut, according to the CDC.
The details of the medical case were published in the Nov. 5 issue of the New England Journal of Medicine
