RESUMO
OBJECTIVE: To evaluate by hysteroscopy and histopathology the influence of tamoxifen in the endometrium of post-menopausal women with previous breast cancer. METHOD: Out of 46 patients studied, 20 of them had been using tamoxifen for an average length of 12 months, and are still being followed-up. Hysteroscopy with endometrial biopsy was performed before and after the use of the drug. RESULTS: The prevalence of endometrial activity before and after this hormoniotherapy was the same, i.e. 10.0%, showing a non-significant variation. CONCLUSION: The hormoniotherapy with tamoxifen has not increased the endometrial proliferactive activity of postmenopausal patients with breast cancer. The most common hysteroscopical finding was numerous vesicles disseminated throughout the uterine cavity probably due to atrophy of the endometrium.