Concurrent tamoxifen-related Müllerian adenofibromas in uterus and ovary.

Tamoxifen is a widely used in anti-oestrogen treatment of breast cancer. Previous reports showed that tamoxifen is associated with proliferative endometrial lesions. We herein reported an unusual case of concurrent hyperplastic lesions in the uterine cavity and right ovary in a 45-year-old woman with tamoxifen therapy. Regular vaginal ultrasonography showed the progressive endometrial thickening and right ovary enlargement during the period of drug use. Both lesions in the uterine cavity and right ovary showed characteristics resembling that of Müllerian adenofibroma. There were also foci of endometriosis in her bilateral ovarian surfaces. We suggest that women taking tamoxifen with a known history of endometriosis should be followed with transvaginal ultrasonography periodically.