Postmenopausal hydrometra. Influence of tamoxifen

Vaginal ultrasonography of the uterus using a high frequency endocavitary probe was performed in 300 postmenopausal women: 150 receiving no replacement nor suppressive hormone therapy and 150 receiving adjuvant anti-estrogen treatment in the form of tamoxifen because of breast cancer. Evidence was found of hydrometra in 84 cases (28%): 10 in the group taking no hormone therapy (6.6%) as compared with 74 in the group exposed to tamoxifen (49.3%). The difference was statistically significant (p < 0.01). In addition, mean thickness of the endometrium was estimated at 6 mm (range: 2-40) in the first group versus 12 mm (range: 3-60) in the second (p < 0.001). It emerged from this comparative ultrasound study that the incidence of postmenopausal hydrometra was influenced by taking tamoxifen. Fluid secretion appearances seen one out of two in treated patients reflect the paradoxical proestrogenic type action of tamoxifen on the uterine mucosa.