A case is reported of a 51-year-old woman who had a hysterectomy and bilateral salpingo-oophorectomy in the same year, following a radical mastoidectomy for breast cancer with metastases to the axillary lymph nodes. Histological examination showed breast cancer metastatic to uterine leiomyoma. The literature about metastasis of extragenital cancer to a leiomyoma is reviewed, and the possible mechanism involved is discussed.