Three women died of breast cancer after receiving organ transplants from the same donor, it has been revealed.
A 53-year-old woman donated her kidneys, lungs, liver, and heart to five patients after she died of a stroke in 2007.
Doctors say that the donor unknowingly passed on cancer cells through her organs, which functioned like a Trojan horse and carried the disease into the patients' bodies.
Four of the five organ recipients died within six years of their life-saving operation: three of the patients died of complications from breast cancer, another died of sepsis after a heart transplant.
The case has raised questions about donor examinations, some of which claim they do not work well enough.
Research by scientists from the University of Tübingen in Germany and the VU University Medical Center in Amsterdam say that the extraordinary case is incredibly rare.
Experts insist that the likelihood of the cancer spreading in a similar fashion could be as low as 0.01 percent.
The first person to be diagnosed with the cancer was a 42-year-old woman who received both lungs of the donor
The woman complained of respiratory problems and was hospitalized only 18 months after her decisive surgery.
Doctors discovered that she had breast cancer that started in her lungs and had already spread to her bones. She later died of the disease after spreading to her liver.
Scientists were able to detect that the cancer came from the donor after analyzing DNA from the cancer cells.
A 32-year-old man who had received a right kidney was warned by the donor and a 62-year-old woman who had received the left kidney, from the risk of cancer emanating from their replacement organs.
The pair received the all-clear after immediate testing, but in 2011, the man was diagnosed with cancer of his liver.
Scientists still call it breast cancer, although it spreads elsewhere because the tumors are made from specific cells that have started in the breast tissue.
His transplanted kidney has been removed and responded well to chemo-drug and has been cancer-free since 2012.
The woman was diagnosed with cancer five years after surgery when doctors found cancer cells in her liver.
Other tests showed that the cancer occurred in the kidney, the bones, the spleen and other organs in the digestive tract.
She died of the disease only two months after her diagnosis and six years after her transplant.
The fourth cancer patient was a 59-year-old woman who had been given a liver to replace her cirrhosis-damaged liver.
She refused to remove the cancerous liver, fearing complications similar to her original surgery in 2007.
Doctors say she initially mastered the disease well – but later she refused to continue treatment and succumbed to her illness in 2014.
According to the results published in the American Journal of Transplantation, cancer has become established because organs without blood supply have remained warm.
The lack of white blood cells in the patient's body may have resulted in the cancer cells locating in the organs before cancer cells and allowing the disease to spread elsewhere.
The patients also received clinical medication to weaken their immune system, which allowed the cancer to take root.
The authors, led by Yvette Matser, wrote: "The disadvantage of a routine postmortem CT scan for all donors is that it increases clinically irrelevant findings, which could lead to more rejection of donors and a decrease in the already scarce donor pool.
"The extremely low transmission rate of malignancies during transplantation demonstrates the efficiency of the current guidelines.
"A full medical examination, including a breast exam, should always be performed as described in the guidelines of the organ harvesting and transplantation network."
They added, "This exceptional case highlights the often fatal consequences of donor breast cancer and suggests that removal of the donor organ and restoration of immunity can bring about complete remission."