A 93-year-old woman was referred to our clinic for abnormal genital bleeding. It was found that she had endometrial hyperplasia and breast cancer. Her uterus was as large as that of a normal adult menstruating woman. She indicated that she had been applying cosmetic cream containing a low concentration of ethynylestradiol to her face and body three times a day for 75 years. It is possible that this long-term use of the ethynylestradiol-containing cream is related to the development of breast cancer and endometrial hyperplasia.