Tapeworm cancer kill a 41 year old HIV positive man

A case published recently in the New England Journal of Medicine informed the world about a man who died after developing tumors made of cancerous parasitic worm tissue in his organs. The 41-old patient was HIV positive and experts are saying that the worm cancer could flourish primarily due to his weakened immune system.

This unusual case got diagnosed through collaboration between United Kingdom’s Natural History Museum and the United States Centers for Disease Control (CDC). A team consisting of Columbian doctors tried to diagnose the man, a couple of years backs. His tumors looked like any normal tumor; the tumors, some of which were over 4 cm wide, were present in different parts of his body including his liver and lungs.

Closer inspections conducted later revealed that the cancerous cells in those tumors were without doubt not human. The doctors found that the cells forming the tumors were only around a tenth of a human cell’s size. Dr. Atis Muehlenbachs of the CDC, the expert responsible for picking up the case on behalf of the US agency, said that initially the finding didn’t make any sense to him and his colleagues.

Dr. Muehlenbachs went through many theories including the ones elaborating shrinking of human cancer cells. He also checked several papers that talked about newly discovered infections. Eventually, after carrying out molecular testing of the tumors, the doctors found that they contain high levels of tapeworm DNA.

This finding also appeared to be something absolutely impossible to Dr. Muehlenbachs. He said that this is the most unusual case he has ever handled and it has given him several sleepless nights. The doctor added that he and his colleagues knew that it was either cancer or an infection, but struggled to confirm what exactly it was for months.


The man became too sick to be treated when the doctors finally managed to detect what exactly caused his tumors. He passed away in Medellin, Columbia just three days following the detection of worm DNA in his tumors.

The worm tissues detected in the tumors of the man belonged to a dwarf tapeworm called Hymenolepis nana. Dr. Peter Olson of the Natural History Museum, who has a specialization on this tapeworm species, informed that this species is unique due to its ability to complete an entire life cycle in a single host.