The development of malignant tumors caused by the ingestion of a parasitic worm in a Colombian resident was identified by genetics from the United States. A case of a peculiar human infection with cancer is described in the New England Journal of Medicine.
A 41-year-old Colombian two years ago went to one of the clinics with complaints about the deteriorating state of health for several months. From the results of the analysis, it became clear that the patient is a carrier of HIV, his intestines are saturated with parasitic worms - dwarf tapeworms, and an aggressive form of oncology develops in the lungs and lymphatic system. At the same time, proteins associated with cancer were absent in the patient's tissues.
After the death of the man in May 2013, samples of his tissues and tumors were sent for study to a group of American geneticists. Scientists have confirmed that the Colombian had some form of cancer - the cells of the neoplasms invaded neighboring tissues, multiplied and grew.
However, these cells were unusually small. The riddle was solved later by tests. Genetic analysis showed that the tumors did not consist of human cells, but of a worm living in the intestines.
Scientists expressed the opinion that some of the larvae did not come out with waste products, as it should be, but "passed" from the gastrointestinal tract to the lymph nodes and spread throughout the body. This was facilitated by the patient's weakened immune system and unusual mutations in the parasite's genome.
According to geneticists, the larvae of dwarf tapeworms contain a large number of stem cells. The latter, due to unusual mutations and a number of chemical signals - present in the human body and not present in the intestines or the wild - begin to multiply uncontrollably in the body.
The researchers note that "parasitic cancer" is a completely new species and its behavior remains to be studied, but it can pose a serious threat in regions of tropical Africa, as well as other parts of the world with high rates of HIV and intestinal parasites.