Apparently, my mother, age 55, was 3 months pregnant before she had an unusual miscarriage that sent her to the hospital. She was complaining of severe abdominal pains, dizziness, and severe vaginal bleeding. They did lots of tests and found she had traces of cancer. They tested her again, and found the cancer cells decreasing on their own. At first, they thought it was ovarian cancer on both sides, so she had a hysterectomy done. After more testing, it was confirmed that she actually had been pregnant, and she aborted on her own a severely mutated fetus. It was either the fetus that contained the cancer or the fibers of the uterine lining that contained the cancer, but my mother sent everything over to the mayo clinic to have it confirmed. I don't remember what this is called, but it's rare. Only 4 out of a million women each year have this trouble.