A German doctor contracted cancer from one of his own patients. The surgeon was performing a tumor operation on the patient when he accidentally cut his finger. The blood from the patient, containing cancer cells, came into contact with the doctor’s wound. Normally, the body would reject and destroy such cells, but the doctor, believing this to be the case, simply applied a bandage to the cut. However, about five months later, he noticed a lump about an inch in size on his finger. Upon consulting a specialist for treatment, he discovered that it was a cancerous tumor. This rare case raises concerns about the potential transmission of cancer cells in such a manner.