Tamoxifen and the uterus: an old drug tested by new modalities.

Tamoxifen has been widely used in the treatment of breast cancer. The effects on the uterus include epithelial metaplasia, hyperplasia and even carcinoma. Transvaginal sonography has been used for visualization of endometrial changes during tamoxifen treatment. However, its use has disclosed that the drug may cause cystic changes in the subendometrial zone without epithelial pathology. Therefore, other sonographic techniques have been suggested for the evaluation of the patient receiving tamoxifen treatment, among them saline contrast hysterosonography and endometrial blood flow studies. These new modalities provide us with tools to evaluate the effect of tamoxifen on the endometrium, prior to the decision to perform invasive procedures.